Dihydrooxazol-2-amine derivatives

ABSTRACT

The invention relates to compounds of formula 
     
       
         
         
             
             
         
       
     
     wherein R 1 , R 2 , R 3 , R 4 , X, Ar, and 
     
       
         
         
             
             
         
       
     
     are defined herein
 
or to a pharmaceutically acceptable acid addition salt thereof. Compounds of formula I have a good affinity to the trace amine associated receptors (TAARs), especially for TAAR1. The compounds can be used for the treatment of depression, anxiety disorders, bipolar disorder, attention deficit hyperactivity disorder (ADHD), stress-related disorders, psychotic disorders such as schizophrenia, neurological diseases such as Parkinson&#39;s disease, neurodegenerative disorders such as Alzheimer&#39;s disease, epilepsy, migraine, hypertension, substance abuse and metabolic disorders such as eating disorders, diabetes, diabetic complications, obesity, dyslipidemia, disorders of energy consumption and assimilation, disorders and malfunction of body temperature homeostasis, disorders of sleep and circadian rhythm and cardiovascular disorders.

PRIORITY TO RELATED APPLICATION(S)

This application is a divisional of U.S. application Ser. No. 13/279,362filed on Oct. 24, 2011, which claims the benefit of European PatentApplication No. 10189624.9, filed Nov. 2, 2010, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The classical biogenic amines (serotonin, norepinephrine, epinephrine,dopamine, histamine) play important roles as neurotransmitters in thecentral and peripheral nervous system [1]. Their synthesis and storage,as well as their degradation and reuptake after release are tightlyregulated. An imbalance in the levels of biogenic amines is known to beresponsible for the altered brain function under many pathologicalconditions [2-5]. A second class of endogenous amine compounds, theso-called trace amines (TAs) significantly overlaps with the classicalbiogenic amines regarding structure, metabolism and subcellularlocalization. The TAs include p-tyramine, β-phenylethylamine, tryptamineand octopamine, and they are present in the mammalian nervous system atgenerally lower levels than classical biogenic amines [6].

Their dysregulation has been linked to various psychiatric diseases likeschizophrenia and depression [7] and for other conditions like attentiondeficit hyperactivity disorder, migraine headache, Parkinson's disease,substance abuse and eating disorders [8,9].

For a long time, TA-specific receptors had only been hypothesized basedon anatomically discrete high-affinity TA binding sites in the CNS ofhumans and other mammals [10,11]. Accordingly, the pharmacologicaleffects of TAs were believed to be mediated through the well knownmachinery of classical biogenic amines, by either triggering theirrelease, inhibiting their reuptake or by “crossreacting” with theirreceptor systems [9,12,13]. This view changed significantly with therecent identification of several members of a novel family of GPCRs, thetrace amine associated receptors (TAARs) [7,14]. There are 9 TAAR genesin human (including 3 pseudogenes) and 16 genes in mouse (including 1pseudogene). The TAAR genes do not contain introns (with one exception,TAAR2 contains 1 intron) and are located next to each other on the samechromosomal segment. The phylogenetic relationship of the receptorgenes, in agreement with an in-depth GPCR pharmacophore similaritycomparison and pharmacological data suggest that these receptors formthree distinct subfamilies [7,14]. TAAR1 is in the first subclass offour genes (TAAR1-4) highly conserved between human and rodents. TAsactivate TAAR1 via Gαs. Dysregulation of TAs was shown to contribute tothe aetiology of various diseases like depression, psychosis, attentiondeficit hyperactivity disorder, substance abuse, Parkinson's disease,migraine headache, eating disorders, metabolic disorders and thereforeTAAR1 ligands have a high potential for the treatment of these diseases.

Therefore, there is a broad interest to increase the knowledge abouttrace amine associated receptors.

References used:

-   1 Deutch, A. Y. and Roth, R. H. (1999) Neurotransmitters. In    Fundamental Neuroscience (2^(nd) edn) (Zigmond, M. J., Bloom, F. E.,    Landis, S. C., Roberts, J. L, and Squire, L. R., eds.), pp. 193-234,    Academic Press;-   2 Wong, M. L. and Licinio, J. (2001) Research and treatment    approaches to depression. Nat. Rev. Neurosci. 2, 343-351;-   3 Carlsson, A. et al. (2001) Interactions between monoamines,    glutamate, and GABA in schizophrenia: new evidence. Annu. Rev.    Pharmacol. Toxicol. 41, 237-260;-   4 Tuite, P. and Riss, J. (2003) Recent developments in the    pharmacological treatment of Parkinson's disease. Expert Opin.    Investig. Drugs 12, 1335-1352,-   5 Castellanos, F. X. and Tannock, R. (2002) Neuroscience of    attention-deficit/hyperactivity disorder: the search for    endophenotypes. Nat. Rev. Neurosci. 3, 617-628;-   6 Usdin, Earl; Sandler, Merton; Editors. Psychopharmacology Series,    Vol. 1: Trace Amines and the Brain. [Proceedings of a Study Group at    the 14th Annual Meeting of the American College of    Neuropsychoparmacology, San Juan, Puerto Rico] (1976);-   7 Lindemann, L. and Hoener, M. (2005) A renaissance in trace amines    inspired by a novel GPCR family. Trends in Pharmacol. Sci. 26,    274-281;-   8 Branchek, T. A. and Blackburn, T. P. (2003) Trace amine receptors    as targets for novel therapeutics: legend, myth and fact. Curr.    Opin. Pharmacol. 3, 90-97;-   9 Premont, R. T. et al. (2001) Following the trace of elusive    amines. Proc. Natl. Acad. Sci. U.S.A. 98, 9474-9475;-   10 Mousseau, D. D. and Butterworth, R. F. (1995) A high-affinity    [3H] tryptamine binding site in human brain. Prog. Brain Res. 106,    285-291;-   11 McCormack, J. K. et al. (1986) Autoradiographic localization of    tryptamine binding sites in the rat and dog central nervous    system. J. Neurosci. 6, 94-101;-   12 Dyck, L. E. (1989) Release of some endogenous trace amines from    rat striatal slices in the presence and absence of a monoamine    oxidase inhibitor. Life Sci. 44, 1149-1156;-   13 Parker, E. M. and Cubeddu, L. X. (1988) Comparative effects of    amphetamine, phenylethylamine and related drugs on dopamine efflux,    dopamine uptake and mazindol binding. J. Pharmacol. Exp. Ther. 245,    199-210;-   14 Lindemann, L. et al. (2005) Trace amine associated receptors form    structurally and functionally distinct subfamilies of novel G    protein-coupled receptors. Genomics 85, 372-385.

SUMMARY OF THE INVENTION

The invention provides compounds of formula

wherein

-   R¹ is hydrogen or lower alkyl;-   R² is hydrogen or is heteroaryl, optionally substituted by one or    more halogen, lower alkyl, lower alkyl substituted by halogen, lower    alkoxy, lower alkoxy substituted by halogen, cyano, S-lower alkyl,    S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or    C₃₋₆-cycloalkyl;-   R³ is hydrogen, halogen, lower alkyl, lower alkyl substituted by    halogen, lower alkoxy, lower alkoxy substituted by halogen, cyano,    S-lower alkyl, S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl    or C₃₋₆-cycloalkyl;-   R⁴ is hydrogen or lower alkyl;

is phenyl or pyridinyl, wherein the N-atom may be in differentpositions;

-   X is a bond or CH(CF₃)—;-   Ar is aryl or heteroaryl, optionally substituted by one or more R³;    or a pharmaceutically suitable acid addition salt thereof.

The invention includes all racemic mixtures, all their correspondingenantiomers and/or optical isomers. In addition, all tautomeric forms ofcompounds of formula I are also encompassed by the present invention.

Compounds of formula I have a good affinity to the trace amineassociated receptors (TAARs), especially for TAAR1.

The compounds can be used for the treatment of depression, anxietydisorders, bipolar disorder, attention deficit hyperactivity disorder(ADHD), stress-related disorders, psychotic disorders such asschizophrenia, neurological diseases such as Parkinson's disease,neurodegenerative disorders such as Alzheimer's disease, epilepsy,migraine, hypertension, substance abuse and metabolic disorders such aseating disorders, diabetes, diabetic complications, obesity,dyslipidemia, disorders of energy consumption and assimilation,disorders and malfunction of body temperature homeostasis, disorders ofsleep and circadian rhythm, and cardiovascular disorders.

Some of the physiological effects (i.e. cardiovascular effects,hypotension, induction of sedation) which have been reported forcompounds which may bind to adrenergic receptors (WO02/076950,WO97/12874 or EP 0717 037) may be considered to be undesirable sideeffects in the case of medicaments aimed at treating diseases of thecentral nervous system as described above. Therefore it is desirable toobtain medicaments having selectivity for the TAAR1 receptor vs.adrenergic receptors. Compounds of the present invention showselectivity for TAAR1 receptor over adrenergic receptors, in particulargood selectivity vs. the human and rat alpha1 and alpha2 adrenergicreceptors.

The present invention provides new compounds of formula I and theirpharmaceutically acceptable salts, pharmaceutical compositionscontaining them, and methods for the manufacture of the compounds andocmpositions. The present invention further provides methods for thetreatment of diseases related to the biological function of the traceamine associated receptors, their manufacture and medicaments based on acompound in accordance with the invention in the control or preventionof illnesses such as depression, anxiety disorders, bipolar disorder,attention deficit hyperactivity disorder, stress-related disorders,psychotic disorders such as schizophrenia, neurological diseases such asParkinson's disease, neurodegenerative disorders such as Alzheimer'sdisease, epilepsy, migraine, substance abuse and metabolic disorderssuch as eating disorders, diabetes, diabetic complications, obesity,dyslipidemia, disorders of energy consumption and assimilation,disorders and malfunction of body temperature homeostasis, disorders ofsleep and circadian rhythm, and cardiovascular disorders.

The preferred indications using the compounds of the present inventionare depression, psychosis, Parkinson's disease, diabetes, anxiety andattention deficit hyperactivity disorder (ADHD).

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “lower alkyl” denotes a saturated straight- orbranched-chain group containing from 1 to 7 carbon atoms, for example,methyl, ethyl, propyl, isopropyl, n-butyl, i-butyl, 2-butyl, t-butyl andthe like. Preferred alkyl groups are groups with 1-4 carbon atoms.

As used herein, the term “lower alkoxy” denotes a group wherein an alkylresidue as defined above is attached via an oxygen atom.

As used herein, the term “lower alkyl substituted by halogen” denotes analkyl group as defined above, wherein at least one hydrogen atom isreplaced by halogen, for example CF₃, CHF₂, CH₂F, CH₂CF₃, CH₂CH₂CF₃,CH₂CF₂CF₃ and the like.

As used herein, the term “lower alkoxy substituted by halogen” denotes agroup wherein the alkyl residue is as defined above and which isattached via an oxygen atom and wherein at least on hydrogen atom isreplaced by halogen.

The term “halogen” denotes chlorine, iodine, fluorine and bromine.

The term “cycloalkyl” is an alkylene ring containing from 3 to 6 carbonring atoms.

The term “aryl” denotes an aromatic carbon ring such as phenyl ornaphthyl, preferably the phenyl.

The term “heteroaryl” refers to an aromatic 6 membered monocyclic ringor to a 10 membered bicyclic ring which contains 1, 2 or 3 heteroatomsselected from nitrogen, such as pyridinyl, pyridazinyl, pyrimidinyl,pyrazinyl orquinolinyl. Preferred heteroaryl groups are pyridinyl,pyrimidinyl, pyrazinyl or quinolinyl.

The term “pharmaceutically acceptable” denotes an attribute of amaterial which is useful in preparing a pharmaceutical composition thatis generally safe, non-toxic, and neither biologically nor otherwiseundesirable and is acceptable for veterinary as well as humanpharmaceutical use.

The term “pharmaceutically acceptable acid addition salts” embracessalts with inorganic and organic acids, such as hydrochloric acid,nitric acid, sulfuric acid, phosphoric acid, citric acid, formic acid,fumaric acid, maleic acid, acetic acid, succinic acid, tartaric acid,methane-sulfonic acid, p-toluenesulfonic acid and the like.

The term “therapeutically effective amount” denotes an amount of acompound of the present invention that, when administered to a subject,(i) treats or prevents the particular disease, condition or disorder,(ii) attenuates, ameliorates or eliminates one or more symptoms of theparticular disease, condition, or disorder, or (iii) prevents or delaysthe onset of one or more symptoms of the particular disease, conditionor disorder described herein. The therapeutically effective amount willvary depending on the compound, the disease state being treated, theseverity of the disease treated, the age and relative health of thesubject, the route and form of administration, the judgment of theattending medical or veterinary practitioner, and other factors.

One embodiment of the invention provides compounds of formula Ia,

-   R¹ is hydrogen or lower alkyl;-   R² is hydrogen or is heteroaryl, optionally substituted by one or    more halogen, lower alkyl, lower alkyl substituted by halogen, lower    alkoxy, lower alkoxy substituted by halogen, cyano, S-lower alkyl,    S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or    C₃₋₆-cycloalkyl;-   R³ is hydrogen, halogen, lower alkyl, lower alkyl substituted by    halogen, lower alkoxy, lower alkoxy substituted by halogen, cyano,    S-lower alkyl, S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl    or C₃₋₆-cycloalkyl;-   R⁴ is hydrogen or lower alkyl;

is phenyl or pyridinyl, wherein the N-atom may be in differentpositions;

-   Ar is aryl or heteroaryl, optionally substituted by one or more R³;    or a pharmaceutically suitable acid addition salt thereof.

A group of compounds of formula Ia are those, wherein Ar is aryl,selected from phenyl or naphthyl, for example the following compounds:

-   (S)-4-(4-(Naphthalen-1-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(8-Chloronaphthalen-1-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-{2-[4-(4-Chloro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine;-   (S)-4-{2-[4-(4-Chloro-2-fluoro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine;-   (S)-4-{2-[4-(4-Trifluoromethyl-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine;-   (S)-4-{2-[4-(4-Methoxy-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine;-   (S)-4-(4-(3-Methyl-4-(trifluoromethoxy)phenylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-[2-(4-Phenylamino-phenyl)-ethyl]-4,5-dihydro-oxazol-2-ylamine;-   (S)-4-(4-(p-Tolylamino)phenethyl)-4,5-dihydrooxazol-2-amine and-   (S)-4-(4-(3,4-Dichlorophenylamino)phenethyl)-4,5-dihydrooxazol-2-amine.

A further group of compounds disclosed in formula Ia are those, whereinAr is heteroaryl, selected from pyridinyl, pyridazinyl, pyrimidinyl,pyrazinyl and quinolinyl, for example the following compounds

-   (S)-4-(4-(Quinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(5-Fluoropyridin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(6-Methylquinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-trifluoromethyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyridin-2-yl)-amine;-   6-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-nicotinonitrile;-   (S)-4-(4-(6-(Trifluoromethyl)pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-fluoro-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-fluoro-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-fluoro-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrimidin-4-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-trifluoromethyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrazin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyridin-2-yl)-amine;-   6-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrimidin-4-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methoxy-pyrimidin-4-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-methyl-pyrimidin-4-yl)-amine;-   (S)-4-(4-(Pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine    hydrochloride;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methoxy-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyrimidin-2-yl)-amine;-   5-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-chloro-pyrazin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-4-trifluoromethyl-pyridin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrazin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-2-methoxy-pyrimidin-4-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methylsulfanyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyrimidin-2-yl)-amine;-   1-(2-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrimidin-5-yl)-ethanone;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-propyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-chloro-pyrimidin-5-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-bromo-pyrimidin-2-yl)-amine;-   {4-[2-((4S,5S)-2-Amino-5-methyl-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-cyclopropyl-pyrimidin-2-yl)-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethoxy-pyrimidin-2-yl)-amine;-   (S)-4-(4-(5-(Trifluoromethyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(5-tert-Butylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(5-(Pentan-3-yl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   2-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrimidine-5-carbonitrile;-   (S)-4-(4-(5-Cyclobutylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (S)-4-(4-(5-Isopropylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   {4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-2-methyl-phenyl}-(5-chloro-pyrimidin-2-yl)-amine    and-   (S)-4-(4-(5-(2,2,2-Trifluoroethoxy)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine.

A further embodiment provides compounds of formula Ib

-   R¹ is hydrogen or lower alkyl;-   R² is hydrogen or is heteroaryl, optionally substituted by one or    more halogen, lower alkyl, lower alkyl substituted by halogen, lower    alkoxy, lower alkoxy substituted by halogen, cyano, S-lower alkyl,    S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or    C₃₋₆-cycloalkyl;-   R³ is hydrogen, halogen, lower alkyl, lower alkyl substituted by    halogen, lower alkoxy, lower alkoxy substituted by halogen, cyano,    S-lower alkyl, S(O)-lower alkyl, S(O)₂-lower alkyl, C(O)-lower alkyl    or C₃₋₆-cycloalkyl;-   R⁴ is hydrogen or lower alkyl;

is phenyl or pyridinyl, wherein the N-atom may be in differentpositions;

-   Ar is aryl or heteroaryl, optionally substituted by one or more R³;    or a pharmaceutically suitable acid addition salt thereof.

A group of compounds from of Ib are those, wherein Ar is aryl, selectedfrom phenyl or naphthyl, for example the following compounds:

-   (4S)-4-(4-(1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine    (1:1 mixture of epimers);-   (+)-(S)-4-(4-((S)-1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (−)-(S)-4-(4-((R)-1-(4-chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-   (4S)-4-(4-(2,2,2-Trifluoro-1-(3-fluorophenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine    and-   (4S)-4-(4-(2,2,2-Trifluoro-1-(4-(trifluoromethyl)phenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine.

A group of compounds of formula Ib are those, wherein Ar is heteroaryl,selected from pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl andquinolinyl.

A further embodiment of the invention provides compounds of formula I,wherein

is pyridinyl, for example the compound{5-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-pyridin-2-yl}-(5-chloro-pyrimidin-2-yl)-amine.

The present compounds of formula I and their pharmaceutically acceptablesalts can be prepared by methods known in the art, for example, byprocesses described below, which process comprises

a) cyclising a compound of formula

with cyanogen bromide (BrCN) to provide a compound of formula

wherein the definitions for R¹, R², R³, R⁴, Ar and X are as describedabove, and, if desired, converting the compounds obtained intopharmaceutically acceptable acid addition salts.

The preparation of compounds of formula I of the present invention canbe carried out in sequential or convergent synthetic routes. Synthesesof the compounds of the invention are shown in the following schemes 1-5and in the description for preparation of the specific compounds 1-75.The skills required for carrying out the reaction and purification ofthe resulting products are known to those skilled in the art. Thesubstituents and indices used in the following description of theprocesses have the significance given herein before unless indicated tothe contrary.

In more detail, the compounds of formula I can be manufactured by themethods given below, by the methods given in the examples or byanalogous methods. Appropriate reaction conditions for the individualreaction steps are known to a person skilled in the art. The reactionsequence is not limited to the one displayed in schemes 1 to 5, however,depending on the starting materials and their respective reactivity thesequence of reaction steps can be freely altered. Starting materials areeither commercially available or can be prepared by methods analogous tothe methods given below, by methods described in references cited in thedescription or in the examples, or by methods known in the art.

General Procedure

R³, R⁴, and Ar are as described above.

Step A:

Wittig reaction between aldehyde 1 (CAS 95715-87-0) and phosphonateester 2 (4-nitro-benzyl)-phosphonic acid diethyl ester [CAS 2609-49-6]or (3-methyl-4-nitro-benzyl)-phosphonic acid diethyl ester [CAS873458-20-9]) can be accomplished by using a base such as NaH, KOtBu,NaOMe, NaOEt, n-BuLi, LiHMDS, NaHMDS, KHMDS, LDA in a solvent such asTHF, dioxane, acetonitrile, 1,2-dimethoxyethane, DMF, benzene, tolueneor mixtures thereof at temperatures from −78° C. to 80° C. for 15 min 8hrs and if appropriate optional addition of a crown ether for ylidegeneration and then condensing the ylide with the carbonyl compound inthe same solvent at a temperature between 0 and 80° C. for 1-24 hrs.Alternatively, the base, the carbonyl compound and the optional crownether can be added to the reaction mixture at the same time withoutpreformation of the ylide at temperatures from −78° C. to 80° C.

Preferred conditions are ylide formation at −78° C. using LDA (preparedin situ from treatment of N,N-diisopropylamine with n-BuLi) as base andTHF as solvent, reacting the phosphonic acid ester for 1 hour at −78°C., and then condensation with the carbonyl component warming to roomtemperature overnight.

Step B:

Reduction of the alkene 3 with concomitant reduction of the nitro groupcan be effected by hydrogenation with hydrogen under normal or elevatedpressure or by transfer hydrogenation using ammonium formate orcyclohexadiene as hydrogen source with a catalyst such as PtO₂, Pd—C orRaney nickel in solvents such as MeOH, EtOH, H₂O, dioxane, THF, HOAc,EtOAc CH₂Cl₂, CHCl₃, DMF or mixtures thereof.

Preferred conditions are ammonium formate in the presence of palladiumon charcoal in MeOH at 50° C. for 1 hour.

Step C:

C—N bond formation can be accomplished by treatment of aryl amine 4 witharyl bromide 5 in the presence of a palladium or copper catalyst, aligand and a base in solvents such as dioxane, DME, THF, toluene, DMFand DMSO at elevated temperatures, for instance using apalladium-catalysed Buchwald-Hartwig reaction.

Preferred conditions are catalytic tris(dibenzylidineacetone)dipalladiumchloroform complex, catalytic9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (xantphos) and caesiumcarbonate in dioxane in a sealed tube heated at 110° C. overnightaccording to a modification of the procedure of van Leeuwen andco-workers (Tetrahedron. Lett. 1999, 40, 3789-3790).

Alternative preferred conditions are catalytic palladium(II) acetate,catalytic 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) andpotassium carbonate in toluene in a sealed tube heated at 110° C. for 1hour according to the procedure of Dommisse and co-workers (Tetrahedron2001, 57, 7027-7034).

Step D:

Simultaneous cleavage of the amino alcohol protecting groups of 6 can beeffected with a mineral acid such as HCl, H₂SO₄ or H₃PO₄ or an organicacid such as CF₃COOH, CHCl₂COOH, HOAc or p-toluonesulfonic acid in asolvent such as CH₂Cl₂, CHCl₃, THF, MeOH, EtOH or H₂O at 0 to 80° C.

Preferred conditions are CF₃COOH in aqueous acetonitrile at 80° C. for 2hours or 4 N HCl in dioxane and THF at 60° C. for 2 hours.

Step E:

Cyclisation of the amino alcohol 7 to the corresponding 2-aminooxazolineIa-1 can be accomplished by treatment with cyanogen bromide in THF assolvent and K₂CO₃ as base at r.t. overnight, or by treatment withcyanogen bromide in methanol as solvent and sodium acetate as base at 0°C. to r.t. overnight followed by treatment with aqueous ammonia solutionat room temperature for 1 hour.

Preferred conditions are methanol as solvent and sodium acetate as baseat r.t. overnight followed by treatment with aqueous ammonia solution atroom temperature for 1 hour.

Step A:

Wittig reaction between aldehyde 2 (CAS 95715-87-0) and(4-bromo-benzyl)-phosphonic acid diethyl ester 8 (CAS 38186-51-5) can beaccomplished by using a base such as NaH, KOtBu, NaOMe, NaOEt, n-BuLi,LiHMDS, NaHMDS, KHMDS, LDA in a solvent such as THF, dioxane,acetonitrile, 1,2-dimethoxyethane, DMF, benzene, toluene or mixturesthereof at temperatures from −78° C. to 80° C. for 15 min-8 hrs and ifappropriate optional addition of a crown ether for ylide generation andthen condensing the ylide with the carbonyl compound in the same solventat a temperature between 0 and 80° C. for 1-24 hrs. Alternatively, thebase, the carbonyl compound and the optional crown ether can be added tothe reaction mixture at the same time without preformation of the ylideat temperatures from −78° C. to 80° C.

Preferred conditions are ylide formation at −78° C. using LDA (preparedin situ from treatment of N,N-diisopropylamine with n-BuLi) as base andTHF as solvent, reacting the phosphonic acid ester for 1 hour at −78°C., and then condensation with the carbonyl component warming to roomtemperature overnight.

Step B:

Simultaneous cleavage of the protecting groups of 9 to afford aminoalcohol 10 can be effected with a mineral acid such as HCl, H₂SO₄ orH₃PO₄ or an organic acid such as CF₃COOH, CHCl₂COOH, HOAc orp-toluonesulfonic acid in a solvent such as CH₂Cl₂, CHCl₃, THF, MeOH,EtOH or H₂O at 0 to 80° C.

Preferred conditions are CF₃COOH in aqueous acetonitrile at 80° C. for 3hours.

Step C:

Selective protection of the amino group of amino alcohol 10 can beeffected by treatment with di-tert-butyl carbonate in the presence of anorganic base such as triethylamine,

-   N,N-diisopropylethylamine or N-methylmorpholine in halogenated    solvents such as dichloromethane or 1,2-dichloroethane or ethereal    solvents such as diethyl ether, dioxane, THF or TBME.

Preferred conditions are N,N-diisopropylethylamine in THF at roomtemperature overnight.

Step D:

Reduction of the olefinic bond of 11 without concomitant cleavage of thearyl-bromine bond can be accomplished by hydrogenation with hydrogenunder normal or elevated pressure with a catalyst such as PtO₂ or Pt/Cin solvents such as MeOH, EtOH, H₂O, dioxane, THF, HOAc, EtOAc CH₂Cl₂,CHCl₃, DMF or mixtures thereof.

Preferred conditions are 10% platinum on charcoal in MeOH at roomtemperature for 3 hours.

Step E:

Oxidation of the alcohol 12 to the corresponding aldehyde 13 can beaccomplished using DMSO-derived oxidation reagents, e.g. DMSO activatedby the use of oxalyl chloride with subsequent treatment withtriethylamine according to the method of Swern, or DMSO activated by useof sulphur trioxide-pyridine complex in the presence of triethylamineaccording to the method of Doering.

Preferred conditions are sulphur trioxide-pyridine complex andtriethylamine in DMSO at a temperature between 0° C. and roomtemperature for 30 min.

Step F:

Nucleophilic addition of a methyl group to aldehyde 13 can beaccomplished by reaction with an organometallic reagent such asmethylmagnesium chloride, methylmagnesium bromide, methylmagnesiumiodide or methyllithium. The reaction is performed in ethereal solventssuch as diethyl ether, dioxane, THF or TBME.

Preferred conditions are methylmagnesium bromide in a mixture of THF anddiethyl ether at 0° C. and then at room temperature for 4 hours. Thereaction affords alcohol 14 as a mixture of epimers which need not beseparated at this stage.

Step G:

Protection of alcohol 14 as a cyclic aminal can be accomplished bytreatment with 2,2-dimethoxypropane in the presence of a catalyticamount of an organic acid such as p-toluenesulphonic acid orcamphorsulphonic acid. The reaction can be performed using excess2,2-dimethoxypropane as solvent, or in the presence of additionalnon-protic co-solvents such as halogenated solvents such asdichloromethane or 1,2-dichloroethane or ethereal solvents such asdiethyl ether, dioxane, THF or TBME. The reaction can be performed atroom temperature or at an elevated temperature such as the refluxtemperature of the solvent.

Preferred conditions are p-toluenesulphonic acid in dichloromethane atroom temperature overnight.

The reaction affords epimeric products 15 & 16 which can be readilyseparated by chomatography at this stage.

Step H:

C—N bond formation to afford imine 17 can be accomplished by couplingreaction between aryl bromide 15 and diphenylmethanimine in the presenceof a palladium or copper catalyst, a ligand and a base in solvents suchas dioxane, DME, THF, toluene, and DMF at elevated temperatures.

Preferred conditions are Pd₂(dba)₃, BINAP and sodium tert-butoxide intoluene at 100° C. overnight.

Step I:

Deprotection of imine 17 to afford aniline 18 can be accomplished byhydrogenation with hydrogen under normal or elevated pressure or bytransfer hydrogenation using ammonium formiate or cyclohexadiene ashydrogen source with a catalyst such as PtO₂, Pt/C or Pd/C in solventssuch as MeOH, EtOH, H₂O, dioxane, THF, HOAc, EtOAc CH₂Cl₂, CHCl₃, DMF ormixtures thereof.

Preferred conditions are 10% palladium on charcoal and ammonium formatein MeOH at 60° C. for 1 hour.

Aryl bromide 16 can be converted to aniline 19 following a similarsequence of reaction steps H and I.

Step A:

C—N bond formation can be accomplished by treatment of aryl amine 18with aryl bromide 5 in the presence of a palladium or copper catalyst, aligand and a base in solvents such as dioxane, DME, THF, toluene, DMFand DMSO at elevated temperatures, for instance using apalladium-catalysed Buchwald-Hartwig reaction.

Preferred conditions are catalytic tris(dibenzylidineacetone)dipalladiumchloroform complex, catalytic9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (xantphos) and caesiumcarbonate in dioxane in a sealed tube heated at 110° C. overnightaccording to a modification of the procedure of van Leeuwen andco-workers (Tetrahedron. Lett. 1999, 40, 3789-3790).

Alternative preferred conditions are catalytic palladium(II) acetate,catalytic 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) andpotassium carbonate in toluene in a sealed tube heated at 110° C. for 1hour according to the procedure of Dommisse and co-workers (Tetrahedron2001, 57, 7027-7034).

Step B:

Simultaneous cleavage of the amino alcohol protecting groups of 20 canbe effected with a mineral acid such as HCl, H₂SO₄ or H₃PO₄ or anorganic acid such as CF₃COOH, CHCl₂COOH, HOAc or p-toluonesulfonic acidin a solvent such as CH₂Cl₂, CHCl₃, THF, MeOH, EtOH or H₂O at 0 to 80°C.

Preferred conditions are CF₃COOH in aqueous acetonitrile at 80° C. for 2hours or 4 N HCl in dioxane and THF at 60° C. for 2 hours.

Step C:

Cyclisation of the amino alcohol 21 to the corresponding2-aminooxazoline Ia-2 can be accomplished by treatment with cyanogenbromide in THF as solvent and K₂CO₃ as base at r.t. overnight, or bytreatment with cyanogen bromide in methanol as solvent and sodiumacetate as base at 0° C. to r.t. overnight followed by treatment withaqueous ammonia solution at room temperature for 1 hour.

Preferred conditions are methanol as solvent and sodium acetate as baseat r.t. overnight followed by treatment with aqueous ammonia solution atroom temperature for 1 hour. Amine 19 can be converted to2-aminooxazoline Ia-3 following a similar sequence of reaction steps A,B and C.

Step A:

Wittig reaction between aldehyde 1 (CAS 95715-87-0) and phosphonateester 22 (6-chloro-pyridin-3-ylmethyl)-phosphonic acid diethyl ester[CAS 561066-65-7]) can be accomplished by using a base such as NaH,KOtBu, NaOMe, NaOEt, n-BuLi, LiHMDS, NaHMDS, KHMDS, LDA in a solventsuch as THF, dioxane, acetonitrile, 1,2-dimethoxyethane, DMF, benzene,toluene or mixtures thereof at temperatures from −78° C. to 80° C. for15 min 8 hrs and if appropriate optional addition of a crown ether forglide generation and then condensing the ylide with the carbonylcompound in the same solvent at a temperature between 0 and 80° C. for1-24 hrs. Alternatively, the base, the carbonyl compound and theoptional crown ether can be added to the reaction mixture at the sametime without preformation of the ylide at temperatures from −78° C. to80° C.

Preferred conditions are ylide formation at −78° C. using LDA (preparedin situ from treatment of N,N-diisopropylamine with n-BuLi) as base andTHF as solvent, reacting the phosphonic acid ester for 1 hour at −78°C., and then condensation with the carbonyl component warming to roomtemperature overnight.

Step B:

Reduction of the alkene 23 without concomitant reduction of the chlorogroup can be effected by hydrogenation with hydrogen under normal orelevated pressure with a catalyst such as PtO₂ or Pt-C in solvents suchas MeOH, EtOH, H₂O, dioxane, THF, HOAc, EtOAc CH₂Cl₂, CHCl₃, DMF ormixtures thereof.

Preferred conditions are hydrogenation in the presence of platinum oncharcoal as catalyst with MeOH as solvent at room temperature andatmospheric pressure for 15 minutes.

Step C:

C—N bond formation can be accomplished by treatment of aryl chloride 24with aryl amine 25 in the presence of a palladium or copper catalyst, aligand and a base in solvents such as dioxane, DME, THF, toluene, DMFand DMSO at elevated temperatures, for instance using apalladium-catalysed Buchwald-Hartwig reaction.

Preferred conditions are catalytic tris(dibenzylidineacetone)dipalladiumchloroform complex, catalytic9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (xantphos) and caesiumcarbonate in dioxane in a sealed tube heated at 100° C. overnightaccording to a modification of the procedure of van Leeuwen andco-workers (Tetrahedron. Lett. 1999, 40, 3789-3790).

Step D:

Simultaneous cleavage of the amino alcohol protecting groups of 26 canbe effected with a mineral acid such as HCl, H₂SO₄ or H₃PO₄ or anorganic acid such as CF₃COOH, CHCl₂COOH, HOAc or p-toluonesulfonic acidin a solvent such as CH₂Cl₂, CHCl₃, THF, MeOH, EtOH or H₂O at 0 to 80°C.

Preferred conditions are CF₃COOH in aqueous acetonitrile at 80° C. for 2hours or 4 N HCl in dioxane and THF at 60° C. for 2 hours.

Step E:

Cyclisation of the amino alcohol 27 to the corresponding2-aminooxazoline Ia-4 can be accomplished by treatment with cyanogenbromide in THF as solvent and K₂CO₃ as base at r.t. overnight, or bytreatment with cyanogen bromide in methanol as solvent and sodiumacetate as base at 0° C. to r.t. overnight followed by treatment withaqueous ammonia solution at room temperature for 1 hour.

Preferred conditions are methanol as solvent and sodium acetate as baseat r.t. overnight followed by treatment with aqueous ammonia solution atroom temperature for 1 hour.

Step A:

Addition of a trifluoromethyl group to aromatic aldehyde 28 can beaccomplished by treatment with (trifluoromethyl)trimethylsilane in thepresence of a source of fluoride ion such as tetrabutylammoniumfluoride.

Preferred conditions are using THF as solvent at 0° C. for 30 minutesand then at room temperature for 2 hours.

Step B:

Conversion of alcohol 29 to the corresponding triflate ester 30 can becan be accomplished by deprotonation with a base such as NaH, KOtBu,n-BuLi, LiHMDS, NaHMDS, KHMDS or LDA in non-protic organic solvents suchas THF, dioxane, 1,2-dimethoxyethane, DMF, benzene, toluene or mixturesthereof at temperatures from −78° C. to 80° C. for 15 min 2 hrs followedby treatment with trifluoromethane sulfonyl chloride.

Preferred conditions are deprotonation at room temperature for 30 minusing sodium hydride as base and diethyl ether as solvent, followed bytreatment with trifluoromethane sulfonyl chloride at room temperaturefor 15 min.

Step C:

C—N bond formation can be accomplished by treatment of triflate 30 witharyl amine 4 in the presence of a base such as NaH, KOtBu, n-BuLi,LiHMDS, NaHMDS, KHMDS or LDA in non-protic organic solvents such as THF,dioxane, 1,2-dimethoxyethane, DMF, benzene, toluene or mixtures thereofat temperatures from −78° C. to 80° C. for 15 min 2 hrs followed bytreatment with trifluoromethane sulfonyl chloride.

Preferred conditions are deprotonation of amine 4 at room temperaturefor 15 min using sodium hydride as base and THF as solvent, followed bytreatment with triflate 30 at room temperature overnight.

Step D:

Simultaneous cleavage of the amino alcohol protecting groups of 31 canbe effected with a mineral acid such as HCl, H₂SO₄ or H₃PO₄ or anorganic acid such as CF₃COOH, CHCl₂COOH, HOAc or p-toluonesulfonic acidin a solvent such as CH₂Cl₂, CHCl₃, THF, MeOH, EtOH or H₂O at 0 to 80°C.

Preferred conditions are CF₃COOH in aqueous acetonitrile at 80° C. for 2hours or 4 N HCl in dioxane and THF at 60° C. for 2 hours.

Step E:

Cyclisation of the amino alcohol 32 to the corresponding2-aminooxazoline Ib-1 can be accomplished by treatment with cyanogenbromide in THF as solvent and K₂CO₃ as base at r.t. overnight, or bytreatment with cyanogen bromide in methanol as solvent and sodiumacetate as base at 0° C. to r.t. overnight followed by treatment withaqueous ammonia solution at room temperature for 1 hour.

Preferred conditions are methanol as solvent and sodium acetate as baseat r.t. overnight followed by treatment with aqueous ammonia solution atroom temperature for 1 hour.

EXPERIMENTAL Example 1(S)-4-(4-(Quinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using8-bromo-quinoline instead of bromobenzene in step a). Yellow solid. MS(ISP): 333.2 ([M+H]⁺).

Example 2(S)-4-(4-(Naphthalen-1-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using1-bromo-naphthalene instead of bromobenzene in step a). Off-white solid.MS (ISP): 332.2 ([M+H]⁺).

Example 3(S)-4-(4-(5-Fluoropyridin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using2-bromo-5-fluoropyridine instead of bromobenzene in step a). Lightyellow oil. MS (ISP): 301.2 ([M+H]⁺).

Example 4(S)-4-(4-(6-Methylquinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using8-bromo-6-methyl-quinoline instead of bromobenzene in step a). Yellowsolid. MS (ISP): 347.2 ([M+H]⁺).

Example 5(S)-4-(4-(8-Chloronaphthalen-1-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using1-bromo-8-chloro-naphthalene instead of bromobenzene in step a).Off-white solid. MS (ISP): 368.1 ([{³⁷Cl}M+H]⁺), 366.1 ([{³⁵Cl}M+H]⁺).

Example 6(S)-4-{2-[4-(4-Chloro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine

a)(S)-2,2-Dimethyl-4-[(E)-2-4-nitro-phenyl)-vinyl]-oxazolidine-3-carboxylicacid tert-butyl ester

To a stirred solution of diisopropylamine (10.9 ml) in THF (350 ml)cooled to −78° C. was added dropwise a solution of n-butyllithium inhexane (48.3 ml, 1.6 M). The cooling bath was removed and the reactionmixture was allowed to warm up to 10° C. before being re-cooled to −78°C. A solution of (4-nitro-benzyl)-phosphonic acid diethyl ester (16.3 g,CAS 2609-49-6) in THF (300 ml) was then added dropwise and the reactionmixture stirred at −78° C. for 1 hour. A solution of(R)-4-formyl-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester(15.0 g, CAS 95715-87-0) in THF (250 ml) was then added dropwise over 1hour and the mixture was then allowed to warm to room temperatureovernight. The mixture was then diluted with ethyl acetate and acidifiedby addition of 2 N aq. hydrochloric acid. The mixture was then washedsequentially with water and saturated brine. The organic phase wasseparated and dried over sodium sulphate and concentrated in vacuo. Thereside was purified by column chromatography (SiO₂; gradient:heptane/EtOAc) to give(S)-2,2-dimethyl-4-[(E)-2-(4-nitro-phenyl)-vinyl]-oxazolidine-3-carboxylicacid tert-butyl ester (15.9 g, 77%) as a yellow oil. MS (EI): 333([M-CH₃]⁺), 292 ([M-C₄H₈]), 277 ([M-CH₃—C₄H₈]⁺), 57 ([C₄H₉]⁺).

b)(S)-4-[2-(4-Amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

To a stirred suspension of(S)-2,2-dimethyl-4-[(E)-2-(4-nitro-phenyl)-vinyl]-oxazolidine-3-carboxylicacid tert-butyl ester (12.0 g) in methanol (500 ml) were added ammoniumformate (32.6 g) and palladium on charcoal (1.83 g, 10 wt %) and themixture was heated at 50° C. for 1 hour. The mixture was then cooled toroom temperature, filtered through celite and the filtrate wasconcentrated in vacuo. The residue was then taken up in ethyl acetateand washed with water. The phases were separated and the organic phasewas dried over sodium sulphate and concentrated in vacuo. The reside waspurified by column chromatography (SiO₂; gradient: heptane/EtOAc) togive(S)-4-[2-(4-amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (8.72 g, 79%) as a yellow oil. MS (ISP): 321.4([M+H]⁺).

c)(S)-4-{2-[4-(4-Chloro-phenylamino)-phenyl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

In a pressure tube,(S)-4-[2-(4-amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (0.3 g), 1-bromo-4-chlorobenzene (215 mg) andcesium carbonate (458 mg) were combined with dioxane (3 ml) to give ayellow suspension. The mixture was degassed by bubbling through argonfor several minutes. Xantphos (32.5 mg) andtris(dibenzylideneacetone)dipalladium chloroform complex (29.1 mg) werethen added and the tube was sealed. The reaction mixture was stirred at110° C. overnight. The reaction mixture was then cooled to roomtemperature and concentrated in vacuo. The residue was purified by flashchromatography (SiO₂; gradient: 0% to 100% EtOAc in hexane) to afford(S)-4-{2-[4-(4-chloro-phenylamino)-phenyl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (228 mg, 57%) as a yellow oil. MS (EI): 432({³⁷Cl}M⁺), 430 ({³⁵Cl}M+H-0H⁺), 376 ({³⁷Cl} [M-C₄H₈]⁺), 374 ({³⁵Cl}[M-C₄H₈]⁺), 231 ({³⁷Cl}[ClC₆H₄NHC₆H₄CH═CH₂]⁺), 229({³⁵Cl}[ClC₆H₄NHC₆H₄CH═CH₂]⁺), 57 ([C₄H₉]⁺).

d) (S)-2-Amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol

To a solution of(S)-4-{2-[4-(4-chloro-phenylamino)-phenyl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (220 mg) in THF (3 ml) in a pressure tube wasadded HCl solution (2.55 ml, 4 M solution in dioxane). The tube wassealed and the reaction mixture was shaken at 60° C. for 2 hours. Themixture was then cooled to room temperature and poured into 1 M aq. NaOHand extracted with EtOAc. The phases were then separated and the organicphase was dried over sodium sulphate and concentrated in vacuo to afford(S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol (148 mg,quant.) as a yellow oil which was used in the next step without furtherpurification. MS (ISP): 293.0 ([{³⁷Cl}M+H]⁺), 291.1 ([{³⁵Cl}M+H]⁺).

e)(S)-4-{2-[4-(4-Chloro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine

To a stirred suspension of(S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol (210 mg) andsodium acetate (121 mg) in methanol (5 ml) was added dropwise a solutionof cyanogen bromide (68 mg) in methanol (0.3 ml). The resulting paleyellow solution was then stirred at room temperature for 16 h. Aqueousammonia solution (0.4 ml, 25%) was added dropwise and stirring wascontinued for a further hour. The mixture was then concentrated in vacuoand the residue was purified by column chromatography (Isolute®Flash-NH₂ from Separtis; gradient: heptane/EtOAc/MeOH) to give(S)-4-{2-[4-(4-chloro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine(74 mg, 48%) as a yellow solid. MS (ISP): 318.1 ([{³⁷Cl}M+H]⁺), 316.1([{³⁵Cl}M+H]⁺).

Example 7(S)-4-{2-[4-(4-Chloro-2-fluoro-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine

The title compound was obtained in analogy to example 6 using1-bromo-4-chloro-2-fluorobenzene instead of 1-bromo-4-chlorobenzene instep c). Off-white solid. MS (ISP): 336.1 ([{³⁷Cl}M+H]⁺), 334.1([{³⁵Cl}M+H]⁺).

Example 8(S)-4-{2-[4-(4-Trifluoromethyl-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine

The title compound was obtained in analogy to example 6 using1-bromo-4-(trifluoromethyl)benzene instead of 1-bromo-4-chlorobenzene instep c). Off-white solid. MS (ISP): 350.1 ([M+H]⁺).

Example 9(S)-4-{2-[4-(4-Methoxy-phenylamino)-phenyl]-ethyl}-4,5-dihydro-oxazol-2-ylamine

The title compound was obtained in analogy to example 6 using1-bromo-4-methoxybenzene instead of 1-bromo-4-chlorobenzene in step c).Off-white solid. MS (ISP): 312.2 ([M+H]⁺).

Example 10(S)-4-(4-(3-Methyl-4-(trifluoromethoxy)phenylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 6 using4-bromo-2-methyl-1-(trifluoromethoxy)benzene instead of1-bromo-4-chlorobenzene in step c). Off-white solid. MS (ISP): 380.2([M+H]⁺).

Example 11{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-trifluoromethyl-pyridin-2-yl)-amine

a)(S)-2,2-Dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester

In a pressure tube,(S)-4-[2-(4-amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (100 mg), 2-chloro-5-(trifluoromethyl)pyridine (57mg) and potassium carbonate (431 mg) were combined with toluene (1 ml)to give a yellow solution. The mixture was degassed by bubbling throughargon for several minutes. BINAP (12 mg) and palladium(II) acetate (2mg) were then added and the tube was sealed. The reaction mixture wasstirred at 110° C. for 1 hour. The reaction mixture was then cooled toroom temperature and concentrated in vacuo. The residue was purified byflash chromatography (SiO₂; gradient: 0% to 40% EtOAc in hexane) toafford(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester (55 mg, 38%) as a yellow amorphous solid. MS(ISP): 466.3 ([M+H]⁺), 410.2 ([M+H—C₄H₈]⁺), 366.2 ([M+H—C₄H₈—CO₂]⁺).

b)(S)-2-Amino-4-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-butan-1-ol

To a solution of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester (54 mg) in acetonitrile (0.5 ml) were added water(1.5 ml) and trifluoroacetic acid (0.071 ml). The mixture was heated at80° C. for 2 h. The mixture was then cooled to room temperature anddiluted with ethyl acetate. The resulting mixture was washedsequentially with 1 N aq. sodium hydroxide solution and saturated brine,the phases were then separated and the organic phase was dried oversodium sulphate and concentrated in vacuo to afford(S)-2-amino-4-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-butan-1-ol(38 mg, quant.) as a yellow oil which was used in the next step withoutfurther purification. MS (ISP): 326.3 ([M+H]⁺).

c){4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-trifluoromethyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 351.2 ([M+H]⁺).

Example 12(S)-6,6′-(4-(2-(2-Amino-4,5-dihydrooxazol-4-yl)ethyl)phenylazanediyl)dinicotinonitrile

The title compound was obtained in analogy to example 11 using6-chloronicotinonitrile instead of 2-chloro-5-(trifluoromethyl)pyridinein step a). Yellow amorphous solid. MS (ISP): 410.2 ([M+H]⁺).

Example 13(S)-4-[2-(4-Phenylamino-phenyl)-ethyl]-4,5-dihydro-oxazol-2-ylamine

a)(S)-2,2-Dimethyl-4-[2-(4-phenylamino-phenyl)-ethyl]-oxazolidine-3-carboxylicacid tert-butyl ester

The title compound was obtained in analogy to example 6 steps a)-c)using bromobenzene instead of 1-bromo-4-chlorobenzene in step c). Yellowoil. MS (ISP): 397.2 ([M+H]⁺), 297.3 ([M+H—C₄H₈—CO₂]⁺).

b) (S)-2-Amino-4-(4-phenylamino-phenyl)-butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-2,2-dimethyl-4-[2-(4-phenylamino-phenyl)-ethyl]-oxazolidine-3-carboxylicacid tert-butyl ester in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. Yellow solid. MS (ISP): 257.2 ([M+H]⁺).

c){4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-trifluoromethyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-(4-phenylamino-phenyl)-butan-1-ol instead of(S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol. Off-whitesolid. MS (ISP): 282.2 ([M+H]⁺).

Example 14 (S)-4-(4-(p-Tolylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using1-bromo-4-methylbenzene instead of bromobenzene in step a). Off-whitesolid MS (ISP): 296.2 ([M+H]⁺).

Example 15{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,5-dichloropyridine instead of bromobenzene in step a). Off-white solidMS (ISP): 319.1 ([{³⁷Cl}M+H]⁺), 317.1 ([{³⁵Cl}M+H]⁺).

Example 166-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-nicotinonitrile

The title compound was obtained in analogy to example 13 using6-chloronicotinonitrile instead of bromobenzene in step a). Off-whitesolid MS (ISP): 308.2 ([M+H]⁺).

Example 17(S)-4-(4-(6-(Trifluoromethyl)pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using4-chloro-6-(trifluoromethyl)pyrimidine instead of bromobenzene in stepa). White solid MS (ISP): 352.1 ([M+H]⁺).

Example 18{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,5-dichloropyrimidine instead of bromobenzene in step a). White solidMS (ISP): 320.1 ([{³⁷Cl}M+H]⁺), 318.1 ([{³⁵Cl}M+H]⁺).

Example 19(S)-4-(4-(3,4-Dichlorophenylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using4-bromo-1,2-dichlorobenzene instead of bromobenzene in step a).Colourless amorphous solid MS (ISP): 354.1 ([{³⁷Cl}M+H]⁺), 352.1([{³⁷Cl³⁵Cl}M+H]⁺), 350.1 ([{³⁵Cl}M+H]⁺).

Example 20{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-fluoro-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-fluoropyrimidine instead of bromobenzene in step a). Whitesolid MS (ISP): 302.1 ([M+H]⁺).

Example 21{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-fluoro-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-3-fluoropyridine instead of bromobenzene in step a). Colourlessoil. MS (ISP): 301.1 ([M+H]⁺).

Example 22{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-fluoro-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-fluoropyridine instead of bromobenzene in step a). Lightyellow solid. MS (ISP): 301.1 ([M+H]⁺).

Example 23{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-trifluoromethlypyridine instead of bromobenzene in step a).Light yellow solid. MS (ISP): 351.1 ([M+H]⁺).

Example 24{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrimidin-4-yl)-amine

The title compound was obtained in analogy to example 13 using4-chloro-6-methylpyrimidine instead of bromobenzene in step a). Lightyellow solid. MS (ISP): 298.2 ([M+H]⁺).

Example 25{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-6-methlypyridine instead of bromobenzene in step a). Lightyellow solid. MS (ISP): 297.2 ([M+H]⁺).

Example 26{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-trifluoromethyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-6-trifluoromethlypyridine instead of bromobenzene in step a).Light yellow solid. MS (ISP): 351.1 ([M+H]⁺).

Example 27{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrazin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,6-dichloro-pyrazine instead of bromobenzene in step a). Yellow solid.MS (ISP): 320.1 ([{³⁷Cl}M+H]⁺), 318.1 ([{³⁵Cl}M+H]⁺).

Example 28{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,6-dichloro-pyridine instead of bromobenzene in step a). Colourlesssolid. MS (ISP): 319.1 ([{³⁷Cl}M+H]⁺), 317.1 ([{³⁵Cl}M+H]⁺).

Example 29{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-methlypyridine instead of bromobenzene in step a). Colourlesssolid. MS (ISP): 297.2 ([M+H]⁺).

Example 30{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-methoxypyridine instead of bromobenzene in step a).Colourless solid. MS (ISP): 313.2 ([M+H]⁺).

Example 316-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile

The title compound was obtained in analogy to example 13 using6-cyano-2-chloropyrazine instead of bromobenzene in step a). Colourlesssolid. MS (ISP): 309.1 ([M+H]⁺).

Example 32{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrimidin-4-yl)-amine

The title compound was obtained in analogy to example 13 using4,6-dichloropyrimidine instead of bromobenzene in step a). White solid.MS (ISP): 320.1 ([{³⁷Cl}M+H]⁺), 318.1 ([{³⁵Cl}M+H]⁺).

Example 33{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methoxy-pyrimidin-4-yl)-amine

The title compound was obtained in analogy to example 13 using4-chloro-6-methoxypyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 314.2 ([M+H]⁺).

Example 34{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-methyl-pyrimidin-4-yl)-amine

The title compound was obtained in analogy to example 13 using4-chloro-2-methylpyrimidine instead of bromobenzene in step a).Off-white solid. MS (ISP): 298.2 ([M+H]⁺).

Example 35(S)-4-(4-(Pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-aminehydrochloride

{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrimidin-4-yl)-amine(16 mg, Example 32) was dissolved in methanol to give a colourlesssolution. The mixture was degassed by bubbling through argon for severalminutes. 10% Palladium on charcoal (11 mg) was added and the reactionmixture was stirred under a hydrogen-filled balloon at room temperaturefor 2 hours. The reaction mixture was filtered through celite and thefiltrate was concentrated in vacuo to afford(S)-4-(4-(pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-aminehydrochloride (14 mg, 87%) as a white solid. MS (ISP): 284.2 ([M+H]⁺).

Example 36{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methoxy-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-methoxypyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 314.2 ([M+H]⁺).

Example 37{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-ethylpyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 312.2 ([M+H]⁺).

Example 38{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-methoxypyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 314.2 ([M+H]⁺).

Example 395-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile

The title compound was obtained in analogy to example 13 using5-cyano-2-chloropyrazine instead of bromobenzene in step a). Yellowsolid. MS (ISP): 309.1 ([M+H]⁺).

Example 40{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-(trifluoromethyl)pyrimidine instead of bromobenzene in stepa). Light yellow solid. MS (ISP): 352.1 ([M+H]⁺).

Example 41{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-chloro-pyrazin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,3-dichloropyrazine instead of bromobenzene in step a). Yellow solid.MS (ISP): 320.1 ([{³⁷Cl}M+H]⁺), 318.1 ([{³⁵Cl}M+H]⁺).

Example 42{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-4-trifluoromethyl-pyridin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,6-dichloro-4-trifluoromethylpyridine instead of bromobenzene in stepa). White solid. MS (ISP): 387.1 ([{³⁷Cl}M+H]⁺), 385.1 ([{³⁵Cl}M+H]⁺).

Example 43{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrazin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-6-methylpyrazine instead of bromobenzene in step a). Lightyellow solid. MS (ISP): 298.2 ([M+H]⁺).

Example 44{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-2-methoxy-pyrimidin-4-yl)-amine

The title compound was obtained in analogy to example 13 using4,6-dichloro-2-methoxypyrimidine instead of bromobenzene in step a).White solid. MS (ISP): 350.3 ([{³⁷Cl}M+H]⁺), 348.2 ([{³⁵Cl}M+H]⁺).

Example 45{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methylsulfanyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-(methylthio)pyrimidine instead of bromobenzene in step a).Amorphous yellow solid. MS (ISP): 330.1 ([M+H]⁺).

Example 46{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-methyl-pyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 298.2 ([M+H]⁺).

Example 471-(2-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]phenylamino}-pyrimidin-5-yl)-ethanone

The title compound was obtained in analogy to example 13 using1-(2-chloro-pyrimidin-5-yl)-ethanone instead of bromobenzene in step a).White solid. MS (ISP): 326.2 ([M+H]⁺).

Example 48{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-4-methyl-pyrimidine instead of bromobenzene in step a).Amorphous colourless solid. MS (ISP): 298.2 ([M+H]⁺).

Example 49{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-propyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-propylpyrimidine instead of bromobenzene in step a). Lightyellow solid. MS (ISP): 326.2 ([M+H]⁺).

Example 50{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-chloro-pyrimidin-5-yl)-amine

The title compound was obtained in analogy to example 13 using5-bromo-2-chloropyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 320.1 ([{³⁷Cl}M+H]⁺), 318.1 ([{³⁵Cl}M+H]⁺).

Example 51{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-bromo-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2,5-dibromopyrimidine instead of bromobenzene in step a). White solid.MS (ISP): 364.1 ([{⁸¹Br}M+H]⁺), 362.1 ([{⁷⁹Br} M+H]⁺).

Example 52{4-[2-((4S,5S)-2-Amino-5-methyl-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine

a) (S,E)-tert-Butyl4-(4-bromostyryl)-2,2-dimethyloxazolidine-3-carboxylate

The title compound was obtained in analogy to example 6(a) using(4-bromo-benzyl)-phosphonic acid diethyl ester instead of(4-nitro-benzyl)-phosphonic acid diethyl ester. Yellow solid. MS (ISP):284.0 ([{⁸¹Br}M+H—C₄H₈—CO₂]⁺), 282.0 ([{⁷⁹Br} M+H—C₄H₈—CO₂]⁺).

b) (E)-(S)-2-Amino-4-(4-bromo-phenyl)-but-3-en-1-ol

To a solution of (S,E)-tert-butyl4-(4-bromostyryl)-2,2-dimethyloxazolidine-3-carboxylate (13 g) inacetonitrile (30 ml) were added sequentially water (35 ml) and asolution of trifluoroacetic acid (18.3 ml) in water (50 ml). The mixturewas heated at 80° C. for 3 hours. The mixture was then cooled to roomtemperature and diluted with ethyl acetate/THF (1:1). The resultingmixture was washed sequentially with 1 N aq. sodium hydroxide solutionand saturated brine, the phases were then separated and the organicphase was dried over sodium sulphate and concentrated in vacuo. Theresidue was triturated in diethyl ether (40 ml) and the resultingcrystals were collected by filtration to afford(E)-(S)-2-amino-4-(4-bromo-phenyl)-but-3-en-1-ol (5.59 g, 68%) as abrown solid. The filtrate was concentrated in vacuo and the residue waspurified by column chromatography (SiO₂; gradient: 0-30% MeOH indichloromethane) to afford a further amount of(E)-(S)-2-amino-4-(4-bromo-phenyl)-but-3-en-1-ol (2.21 g, 27%) as abrown solid. MS (ISP): 227.1 ([{⁸¹Br}M+H—NH₃]⁺), 225.1 ([{⁷⁹Br}M+H—NH₃]⁺).

c) [(E)-(S)-3-(4-Bromo-phenyl)-1-hydroxymethyl-allyl]-carbamic acidtert-butyl ester

(E)-(S)-2-amino-4-(4-bromo-phenyl)-but-3-en-1-ol (7.8 g) andN,N-diisopropylethylamine (11.1 ml) were combined with THF (150 ml) togive a colourless solution. The reaction mixture was cooled to 0° C. anddi-tert-butyl carbonate (7.17 g) was added. The reaction mixture wasstirred at room temperature overnight to afford a yellow solution. Thereaction mixture was then poured into EtOAc and washed sequentially with1 M aq. HCl, 1 M aq. NaOH and saturated brine. The organic layer wasdried over Na2SO4, filtered, and the filtrate was then stirred overcharcoal (2 g) for 30 min. The mixture was then filtered through celiteand the filtrate was concentrated in vacuo to afford[(E)-(S)-3-(4-bromo-phenyl)-1-hydroxymethyl-allyl]-carbamic acidtert-butyl ester as an off-white solid (10.8 g, 98%). MS (ISP): 344.0([{⁸¹Br}M+H]⁺), 342.0 ([{⁷⁹Br} M+H]⁺), 287.9 ([{⁸¹Br}M+H—C₄H₈]⁺), 286.0([{⁷⁹Br} M+H—C₄H₈]⁺).

d) [(S)-3-(4-Bromo-phenyl)-1-hydroxymethyl-propyl]-carbamic acidtert-butyl ester

To a solution of[(E)-(S)-3-(4-bromo-phenyl)-1-hydroxymethyl-allyl]-carbamic acidtert-butyl ester (14.7 g) in methanol (150 ml) was added 10% Pt/C (1.68g) and the resulting mixture was stirred under a H₂ balloon at roomtemperature for 3 hours (whereby the reaction progress was checkedcontinuously by ¹H NMR). The reaction mixture was filtered throughcelite and the filtrate was concentrated in vacuo to afford[(S)-3-(4-bromo-phenyl)-1-hydroxymethyl-propyl]-carbamic acid tert-butylester as a yellow solid (11.5 g, 78%). MS (ISP): 346.0 ([{⁸¹Br}M+H]⁺),344.0 ([{⁷⁹Br} M+H]⁺), 289.9 ([{⁸¹Br}M+H—C₄H₈]⁺), 288.0 ([{⁷⁹Br}M+H—C₄H₈]⁺), 246.1 ([{⁸¹Br}M+H—C₄H₈—CO₂]⁺), 244.1 ([{⁷⁹Br}M+H—C₄H₈—CO₂]⁺).

e) [(S)-3-(4-Bromo-phenyl)-1-formyl-propyl]-carbamic acid tert-butylester

To a solution of[(S)-3-(4-bromo-phenyl)-1-hydroxymethyl-propyl]-carbamic acid tert-butylester (11.5 g) and triethylamine (27.9 ml) in DMSO (70 ml) was addeddropwise sulfur trioxide-pyridine complex (16.0 g) while the reactionmixture was cooled in a ice bath. The mixture was then stirred at roomtemperature for 30 min to afford a yellow solution. The reaction mixturewas poured into EtOAc and extracted sequentially with water and withsaturated brine. The organic layer was dried over Na2SO4 andconcentrated in vacuo. The residue was purified by column chromatography(silica gel, heptane/EtOAc 3/1) to afford[(S)-3-(4-bromo-phenyl)-1-formyl-propyl]-carbamic acid tert-butyl esteras a yellow oil (7.3 g, 64%). MS (EI): 343 ([{⁸¹Br}M]⁺), 341,([{⁷⁸Br}M]⁺), 287 ([{⁸¹Br}M−C₄H₈]⁺), 285 ([{⁷⁹Br}M—C₄H₈]⁺), 214([{⁸¹Br}M—C₄H₈—CO₂]⁺), 212 ([{⁷⁹Br}M—C₄H₈—CO₂]⁺), 171, 169, 103, 57([C₄H₉]⁺).

f) {(1S,2RS)-1-[2-(4-Bromo-phenyl)-ethyl]-2-hydroxy-propyl}-carbamicacid tert-but 1 ester

To a stirred, cooled solution of[(S)-3-(4-bromo-phenyl)-1-formyl-propyl]-carbamic acid tert-butyl ester(7.3 g) in THF (40 ml) and Et2O (30 ml) at 0° C. was added dropwise over30 min a solution of methylmagnesium bromide (20.0 ml, 3 M solution inEt2O). The reaction mixture was then stirred at room temperature for 4hours before being quenched by dropwise addition of water (gasformation!). The reaction mixture was then poured into EtOAc, the layerswere separated and the organic layer was washed sequentially withdiluted aq. HCl (pH 5) and saturated brine, then dried over Na2SO4 andconcentrated in vacuo. The residue was purified by flash chromatography(silica gel, gradient: 0% to 80% EtOAc in hexane) to afford{(1S,2RS)-1-[2-(4-bromo-phenyl)-ethyl]-2-hydroxy-propyl}-carbamic acidtert-butyl ester as a colourless amorphous solid comprising a mixture ofepimers (5.1 g, 66%). MS (EI): 303 ([{⁸¹Br}M-C₄H₈]⁺), 301 ([{⁷⁹Br}M-C₄H₈]⁺), 258 ([{⁸¹Br}M-C₄H₈—CO₂H]⁺), 256 ([{⁷⁹Br} M-C₄H₈—CO₂H]⁺), 214,212, 171, 169, 57 ([C₄H₉]⁺).

g)(4S,5S)-4-[2-(4-Bromo-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester and(4S,5R)-4-[2-(4-Bromo-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

{(1S,2RS)-1-[2-(4-bromo-phenyl)-ethyl]-2-hydroxy-propyl}-carbamic acidtert-butyl ester (5.07 g), p-toluenesulfonic acid monohydrate (538 mg)and 2,2-dimethoxypropane (26.1 ml) were combined with CH2Cl2 (300 ml) togive a colourless solution. The reaction mixture was stirred at roomtemperature overnight before being washed with sat. aq. NaHCO3 solution.The layers were separated and the organic layer was dried over Na2SO4and concentrated in vacuo. The residue was purified by flashchromatography (silica gel, gradient: 0% to 25% EtOAc in hexane) toafford(4S,5S)-4-[2-(4-bromo-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester as a yellow oil (2.85 g, 51%, fractions elutingfirst) and(4S,5R)-4-[2-(4-bromo-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester as a yellow oil (475 mg, 8%, fractions elutinglast).

h) (4S,5S)-4-{2-[4-(Benzhydrylidene-amino)-phenyl]-ethyl}-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

To a solution of(4S,5S)-4-[2-(4-bromo-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (3.13 g) in toluene (30 ml) were addeddiphenylmethanimine (1.71 g) and sodium tert-butoxide (1.06 g). Thereaction mixture was degassed by bubbling argon through the mixture forseveral minutes. BINAP (489 mg) and Pd2(dba)₃ (216 mg) were then addedand the reaction mixture was stirred at 100° C. for 20 h. The reactionmixture was then cooled to room temperature, poured into EtOAc, andextracted with water. The organic layer was separated, dried overNa2SO4, and concentrated in vacuo. The residue was purified by flashchromatography (silica gel, gradient: 0% to 30% EtOAc in hexane) toafford(4S,5S)-4-{2-[4-(benzhydrylidene-amino)-phenyl]-ethyl}-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester as a yellow oil (3.2 g, 82%). MS (ISP): 499.3([M+H).

i)(4S,5S)-4-[2-(4-Amino-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

To a solution of(4S,5S)-4-{2-[4-(benzhydrylidene-amino)-phenyl]-ethyl}-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (3.23 g) in methanol (50 ml) was added ammoniumformate (6.13 g). The reaction mixture was degassed by bubbling argonthrough the mixture for several minutes. 10% Pd/C (207 mg) was added andthe reaction mixture was stirred at 60° C. for 1 hour. TLC showed thereaction was complete. The reaction mixture was filtered through celiteand concentrated in vacuo. The residue was purified by flashchromatography (silica gel, gradient: 0% to 100% EtOAc in hexane) toafford(4S,5S)-4-[2-(4-amino-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester as a yellow oil (1.76 g, 81%). MS (ISP): 335.2([M+H), 235.2 ([M-C₄H₈—CO₂]⁺).

j)(4S,5S)-4-{2-[4-(5-Chloro-pyrimidin-2-ylamino)-phenyl]-ethyl}-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

The title compound was obtained in analogy to example 6(c) using(4S,5S)-4-[2-(4-amino-phenyl)-ethyl]-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester instead of(S)-4-[2-(4-amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester and 2,5-dichloropyrimidine instead of1-bromo-4-chlorobenzene. Yellow oil. MS (ISP): 449.2 ([{³⁷Cl}M+H]⁺),447.2 ([{³⁵Cl}M+H]⁺).

k)(2S,3S)-3-Amino-5-[4-(5-chloro-pyrimidin-2-ylamino)-phenyl]-pentan-2-ol

The title compound was obtained in analogy to example 11 step b) using(4S,5S)-4-{2-[4-(5-chloro-pyrimidin-2-ylamino)-phenyl]-ethyl}-2,2,5-trimethyl-oxazolidine-3-carboxylicacid tert-butyl ester in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. White solid. MS (ISP): 309.1 ([{³⁷Cl}M+H]⁺),307.1 ([{³⁵Cl}M+H]⁺).

l){4-[2-((4S,5S)-2-Amino-5-methyl-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 6 step e) using(2S,3S)-3-amino-5-[4-(5-chloro-pyrimidin-2-ylamino)-phenyl]-pentan-2-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 334.1 ([{³⁷Cl}M+H]⁺), 332.1 ([{³⁵Cl}M+H]⁺).

Example 53(S)-1-(2-(4-(2-(2-Amino-4,5-dihydrooxazol-4-yl)ethyl)phenylamino)pyrimidin-5-yl)propan-1-one

The title compound was obtained in analogy to example 13 using1-(2-chloropyrimidin-5-yl)propan-1-one (CAS 212621-61-9) instead ofbromobenzene in step a). Yellow solid. MS (ISP): 340.3 ([M+H]⁺).

Example 54{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-cyclopropyl-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-cyclopropylpyrimidine (CAS 166740-44-9) instead ofbromobenzene in step a). Off-white solid. MS (ISP): 324.3 ([M+H]⁺).

Example 55{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethoxy-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 13 using2-chloro-5-ethoxypyrimidine instead of bromobenzene in step a). Whitesolid. MS (ISP): 328.3 ([M+H]⁺).

Example 56(S)-4-(4-(5-(Trifluoromethyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

a) Trifluoro-methanesulfonic acid 5-trifluoromethyl-pyrimidin-2-yl ester

To a solution of 5-(trifluoromethyl)pyrimidin-2-ol (300 mg) indichloromethane (10 ml) at 0° C. were added dropwiseN,N-diisopropylethylamine (939 μl) and trifluoromethanesulfonicanhydride (185 μl). The reaction mixture was stirred at 0° C. for 2 h.The crude reaction mixture was then concentrated in vacuo to afford ared solid contained trifluoro-methanesulfonic acid5-trifluoromethyl-pyrimidin-2-yl ester which was used immediately in thenext step without further purification.

b)(S)-4-(4-(5-(Trifluoromethyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 usingtrifluoro-methanesulfonic acid 5-trifluoromethyl-pyrimidin-2-yl esterinstead of bromobenzene in step a). Yellow solid. MS (ISP): 352.3([M+H]⁺).

Example 57(S)-4-(4-(5-tert-Butylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

a) (S)-tert-Butyl4-(4-(5-bromopyrimidin-2-ylamino)phenethyl)-2,2-dimethyloxazolidine-3-carboxylate

The title compound was obtained in analogy to example 6 steps a)-c)using 2,5-dibromopyrimidine instead of 1-bromo-4-chlorobenzene in stepc). Yellow oil. MS (ISP): 479.1 ([{⁸¹Br}M+H]⁺), 477.1 ([{⁷⁹Br} M+H]⁺).

b) (S)-tert-Butyl4-(4-(5-tert-butylpyrimidin-2-ylamino)phenethyl)-2,2-dimethyloxazolidine-3-carboxylate

To (S)-tert-butyl4-(4-(5-bromopyrimidin-2-ylamino)phenethyl)-2,2-dimethyloxazolidine-3-carboxylate(100 mg) and bis(tri-t-butylphosphine)palladium(0) (21.4 mg) in THF (10ml) under argon was added tert-butylzinc(II) bromide (1.26 ml, 0.5 Msolution in THF). The reaction mixture was stirred at 22° C. for 1 hour.The reaction was quenched by addition of EtOAc then washed sequentiallywith saturated aqueous ammonium chloride solution and 1 N aqueous sodiumbicarbonate solution. The phases were separated and the organic phasewas dried over MgSO4, filtered and then concentrated in vacuo. The crudematerial was purified by preparative HPLC (Column: Zorbax 5 micron C1850×20, flow rate: 30 ml/min; eluant gradient: water (+0.1% formicacid)/acetonitrile (80%-20% to 5%-95%)) to afford (S)-tert-butyl4-(4-(5-tert-butylpyrimidin-2-ylamino)phenethyl)-2,2-dimethyloxazolidine-3-carboxylate(8.4 mg, 9%) as a yellow oil. MS (ISP): 455.5 ([M+H]⁺).

c) (S)-2-Amino-4-(4-(5-tert-butylpyrimidin-2-ylamino)phenyl)butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-tert-butyl4-(4-(5-tert-butylpyrimidin-2-ylamino)phenethyl)-2,2-dimethyloxazolidine-3-carboxylatein place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. Amorphous solid. MS (ISP): 315.3 ([M+H]⁺).

d)(S)-4-(4-(5-tert-Butylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-(4-(5-tert-butylpyrimidin-2-ylamino)phenyl)butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 340.4 ([M+H]⁺).

Example 58(S)-4-(4-(5-(Pentan-3-yl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 57 usingpentan-3-ylzinc(II) bromide instead of tert-butylzinc(II) bromide instep b). White solid. MS (ISP): 354.3 ([M+H]⁺).

Example 592-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrimidine-5-carbonitrile

The title compound was obtained in analogy to example 13 using2-chloropyrimidine-5-carbonitrile instead of bromobenzene in step a).White solid. MS (ISP): 309.2 ([M+H]⁺).

Example 60(S)-4-(4-(5-Cyclobutylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 57 usingcyclobutylzinc(II) bromide instead of tert-butylzinc(II) bromide in stepb). White solid. MS (ISP): 338.3 ([M+H]⁺).

Example 61(S)-4-(4-(5-Isopropylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 57 usingisopropylzinc(II) bromide instead of tert-butylzinc(II) bromide in stepb). White solid. MS (ISP): 326.3 ([M+H]⁺).

Example 62(S)-4-(2-{4-[1-(5-Bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-ethyl)-4,5-dihydro-oxazol-2-ylamine

a) (RS)-1-(5-Bromo-pyridin-2-yl)-2,2,2-trifluoro-ethanol

To a cooled, stirred solution of 5-bromopyridine-2-carbaldehyde (3.72 g,CAS 31181-90-5) and (trifluoromethyl)trimethylsilane (3.56 ml) in THF(30 ml) at 0° C. was added dropwise tetrabutylammonium fluoride solution(1.0 ml, 1 M solution in THF). The reaction mixture was stirred at 0° C.for 30 min and then at room temperature for 2 hours. The mixture wasthen diluted with 1 N aq. HCl (20 ml) and stirring was continued for afurther 2 hours. The mixture was diluted with water and extracted twicewith ethyl acetate. The combined organic phases were dried over sodiumsulfate and concentrated in vacuo. The residue was purified by columnchromatography (SiO₂; gradient: heptane/EtOAc) to give(RS)-1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethanol as a light yellowsolid (3.35 g, 65%). MS (ISP): 258.0 ([{⁸¹Br}M+H]⁺), 256.1 ([{⁷⁹Br}M+H]⁺).

b) (RS)-Trifluoro-methanesulfonic acid1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethyl ester

To a stirred suspension of sodium hydride (765 mg, 60% dispersion inmineral oil) in dry diethyl ether (20 ml) under an argon atmosphere at0° C. was added dropwise a solution of(RS)-1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethanol (3.06 g) indiethyl ether (10 ml) and the resulting mixture was stirred at roomtemperature for 30 min. Trifluoromethanesulfonyl chloride (1.4 ml) wasadded and stirring was continued for a further 15 min at roomtemperature. The reaction mixture was quenched by addition of 10% aq.sodium bicarbonate solution and the mixture was extracted with diethylether. The phases were separated and the organic phase was washed withsaturared brine. The organic phase was separated, dried over sodiumsulphate, and concentrated in vacuo. The reside was purified byKugelrohr distillation (60° C. oven temperature, 0.3 mbar) to give(RS)-trifluoro-methanesulfonic acid1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethyl ester (3.6 g, 78%) as awhite solid. MS (EI): 389 ([{⁸¹Br}M]⁺), 387 ([{⁷⁹Br}M]⁺), 320([{⁸¹Br}M-CF₃]⁺), 318 ([{⁷⁹Br}M-CF₃]⁺), 256 ([{⁸¹Br}M-CF₃—SO₂]⁺), 254([{⁷⁹Br}M-CF₃—SO₂]⁺), 240 ([{⁸¹Br}M-OSO₂CF₃]⁺), 238([{⁷⁹Br}M-OSO₂CF₃]⁺).

c)(S)-4-(2-{4-[1-(5-Bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-ethyl)-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

To a stirred solution of(S)-4-[2-(4-amino-phenyl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (150 mg, example 6b) in dry THF (0.2 ml) under anargon atmosphere was added sodium hydride (34 mg, 60% dispersion inmineral oil) and stirring was continued for 15 minutes.Trifluoro-methanesulfonic acid1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethyl ester (182 mg) was thenadded and the mixture was stirred overnight at room temperature. Thereaction mixture was diluted with ethyl acetate and washed sequentiallywith water and with saturared brine. The organic phase was separated,dried over sodium sulphate, and concentrated in vacuo. The reside waspurified by column chromatography (SiO₂; gradient: heptane/EtOAc) togive(S)-4-(2-{4-[1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-ethyl)-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (99 mg, 38%) as a yellow oil. MS (ISP): 560.1([{⁸¹Br}M+H]⁺), 558.1 ([{⁷⁹Br}M+H]⁺).

d)(S)-2-Amino-4-{4-[1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-4-(2-{4-[1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-ethyl)-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. Yellow oil. MS (ISP): 420.1 ([{⁸¹Br}M+H]⁺), 418.2([{⁷⁹Br}M+H]⁺).

e)(S)-4-(2-{4-[1-(5-Bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-ethyl)-4,5-dihydro-oxazol-2-ylamine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-{4-[1-(5-bromo-pyridin-2-yl)-2,2,2-trifluoro-ethylamino]-phenyl}-butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.Amorphous yellow solid. MS (ISP): 445.1 ([{⁸¹Br}M+H]⁺), 443.1([{⁷⁹Br}M+H]⁺).

Example 63(4S)-4-(4-(1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine(1:1 mixture of epimers)

The title compound was obtained in analogy to example 62 using4-chloro-benzaldehyde instead of 5-bromopyridine-2-carbaldehyde 1 instep a). Colourless foam. MS (ISP): 400.2 ([{³⁷Cl}M+H]⁺), 398.2([{³⁵Cl}M+H]⁺).

Examples 64 & 65(+)-(S)-4-(4-((S)-1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine&(−)-(S)-4-(4-((R)-1-(4-chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

(4S)-4-(4-(1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine(1:1 mixture of epimers) was separated by preparative chiral HPLC(Chiralpak AD, eluant: heptane/EtOH 6/4). 1^(st) fraction:(+)-(S)-4-(4-((S)-1-(4-chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amineColourless oil. MS (ISP): 400.2 ([{³⁷Cl}M+H]⁺), 398.2 ([{³⁵Cl}M+H]⁺).2^(nd) fraction:(−)-(S)-4-(4-((R)-1-(4-chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amineColourless oil. MS (ISP): 400.2 ([{³⁷Cl}M+H]⁺), 398.2 ([{³⁵Cl}M+H]⁺).

Example 66(4S)-4-(4-(2,2,2-Trifluoro-1-(3-fluorophenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 62 using3-fluoro-benzaldehyde instead of 5-bromopyridine-2-carbaldehyde in stepa). Colourless oil. MS (ISP): 382.2 ([M+H]⁺).

Example 67(4S)-4-(4-(2,2,2-Trifluoro-1-(4-(trifluoromethyl)phenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 62 using4-trifluoromethyl-benzaldehyde instead of 5-bromopyridine-2-carbaldehydein step a). Colourless oil. MS (ISP): 432.2 ([M+H]⁺).

Example 68(4S)-4-(4-(1-(5-Chloropyridin-2-yl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 62 using5-chloropyridine-2-carbaldehyde instead of5-bromopyridine-2-carbaldehyde in step a). Light yellow oil. MS (ISP):401.2 ([{³⁷Cl}M+H]⁺), 399.2 ([{³⁵Cl}M+H]⁺).

Example 69(4S)-4-(4-(1-(3,5-Dichlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 62 using3,5-dichloro-benzaldehyde instead of 5-bromopyridine-2-carbaldehyde instep a). Colourless waxy solid. MS (ISP): 436.2 ([{³⁷Cl}M+H]⁺), 434.2([{³⁷Cl³⁵Cl}M+H]⁺), 432.2 ([{³⁵Cl}M+H]⁺).

Example 70(4S)-4-(4-(2,2,2-Trifluoro-1-(6-methoxypyridin-2-yl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 62 using6-methoxypyridine-2-carbaldehyde instead of5-bromopyridine-2-carbaldehyde in step a). Colourless oil. MS (ISP):395.2 ([M+H]⁺).

Example 71{5-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]pyridin-2-yl}-(5-chloro-pyrimidin-2-yl)-amine

a)(S)-4-[(E)-2-6-Chloro-pyridin-3-yl)-vinyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

The title compound was obtained in analogy to example 6 step (a) using(6-chloro-pyridin-3-ylmethyl)-phosphonic acid diethyl ester (CAS561066-65-7) instead of (4-nitro-benzyl)-phosphonic acid diethyl ester.Yellow oil. MS (ISP): 341.2 ([{³⁷Cl}M+H]⁺), 339.1 ([{³⁵Cl}M+H]⁺).

b)(S)-4-[2-(6-Chloro-pyridin-3-yl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

To a stirred suspension of(S)-4-[(E)-2-(6-chloro-pyridin-3-yl)-vinyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (1.0 g) in methanol (70 ml) was added platinum oncharcoal (0.58 g, 10 wt %) and the mixture was stirred under anatmosphere of hydrogen at room temperature for 15 min. The mixture wasthen filtered through celite and the filtrate was concentrated in vacuoto give(S)-4-[2-(6-chloro-pyridin-3-yl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (949 mg, 94%) as a colourless oil. MS (ISP): 343.2([{³⁷Cl}M+H]⁺), 341.1 ([{³⁵Cl}M+H]⁺), 287.0 ([{³⁷Cl}M+H—C₄H₈]⁺), 285.1([{³⁵Cl}M+H—C₄H₈]⁺)

c)(S)-4-{2-[6-(5-Chloro-pyrimidin-2-ylamino)-pyridin-3-yl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

In a pressure tube,(S)-4-[2-(6-chloro-pyridin-3-yl)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (0.94 g), 5-chloropyrimidin-2-amine (357 mg) andcesium carbonate (1.35 g) were combined with dioxane (5 ml) to give ayellow suspension. The mixture was degassed by bubbling through argonfor several minutes. Xantphos (96 mg) andtris(dibenzylideneacetone)dipalladium chloroform complex (86 mg) werethen added and the tube was sealed. The reaction mixture was stirred at100° C. overnight. The reaction mixture was then cooled to roomtemperature and concentrated in vacuo. The residue was purified by flashchromatography (SiO₂; gradient: 0% to 70% EtOAc in hexane) to afford(S)-4-{2-[6-(5-chloro-pyrimidin-2-ylamino)-pyridin-3-yl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester (417 mg, 35%) as a yellow solid. MS (ISP): 436.3([{³⁷Cl}M+H]⁺), 434.4 ([{³⁵Cl}M+H]⁺), 380.3 ([{³⁷Cl}M+H—C₄H₈]⁺), 378.3([{³⁵Cl}M+H—C₄H₈]⁺).

d)(S)-2-Amino-4-[6-(5-chloro-pyrimidin-2-ylamino)-pyridin-3-yl]-butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-4-{2-[6-(5-chloro-pyrimidin-2-ylamino)-pyridin-3-yl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. Light brown solid. MS (ISP): 296.3([{³⁷Cl}M+H]⁺), 294.1 ([{³⁵Cl}M+H]⁺).

e){5-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-pyridin-2-yl}-(5-chloro-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-[6-(5-chloro-pyrimidin-2-ylamino)-pyridin-3-yl]-butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 321.1 ([{³⁷Cl}M+H]⁺), 319.1 ([{³⁵Cl}M+H]⁺).

Example 72{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-2-methyl-phenyl}-(5-chloro-pyrimidin-2-yl)-amine

a)(S)-4-{2-[4-(5-Chloro-pyrimidin-2-ylamino)-3-methyl-phenyl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester

The title compound was obtained in analogy to example 6 steps a)-c)using (3-methyl-4-nitrobenzyl)-phosphonic acid diethyl ester (CAS873458-20-9) instead of (4-nitro-benzyl)-phosphonic acid diethyl esterin step a) and 2,5-dichloropyrimidine instead of 1-bromo-4-chlorobenzenein step c). Yellow oil. MS (ISP): 449.0 ([{³⁷Cl}M+H]⁺), 447.3([{³⁵Cl}M+H]⁺), 393.3 ([{³⁷Cl}M+H—C₄H₈]⁺), 391.1 ([{³⁵Cl}M+H—C₄H₈]⁺).

b)(S)-2-Amino-4-[4-(5-chloro-pyrimidin-2-ylamino)-3-methyl-phenyl]-butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-4-{2-[4-(5-chloro-pyrimidin-2-ylamino)-3-methyl-phenyl]-ethyl}-2,2-dimethyl-oxazolidine-3-carboxylicacid tert-butyl ester in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. White solid. MS (ISP): 309.2 ([{³⁷Cl}M+H]⁺),307.3 ([{³⁵Cl}M+H]⁺).

c){4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4yl)-ethyl]-2-methyl-phenyl}-5-chloro-pyrimidin-2-yl)-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-[4-(5-chloro-pyrimidin-2-ylamino)-3-methyl-phenyl]-butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.Off-white solid. MS (ISP): 334.1 ([{³⁷Cl}M+H]⁺), 332.1 ([{³⁵Cl}M+H]⁺).

Example 73(S)-4-(4-(5-(2,2,2-Trifluoroethoxy)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

a) 5-Bromo-2-(2,2,2-trifluoro-ethoxy)-pyrimidine

To sodium hydride (303 mg) under an argon atmosphere at 0° C. was addeddropwise 2,2,2-trifluoroethanol (775 μl) and the mixture was thenstirred at RT for 90 min. A solution of 2,5-dibromopyrimidine (1.5 g) inDMF (8 ml) was then added and stirring continued at RT for 2 hours. Thereaction mixture was poured into ice (50 mL) and extracted with EtOAc(2×50 mL). The organic layers were dried over MgSO₄ and concentrated invacuo to afford 5-bromo-2-(2,2,2-trifluoro-ethoxy)-pyrimidine (790 mg,49%) as a yellow oil which was used in the next step without furtherpurification. MS (EI): 258 ([{⁸¹Br}M]⁺), 256 ([{⁷⁹Br}M]⁺), 189([{⁸¹Br}M—CF₃]⁺), 187 ([{79Br}M-CF₃]⁺).

b)(S)-4-(4-(5-(2,2,2-Trifluoroethoxy)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 13 using5-bromo-2-(2,2,2-trifluoro-ethoxy)-pyrimidine instead of bromobenzene instep a). Yellow oil. MS (ISP): 382.2 ([M+H]⁺).

Example 74(S)-4-(4-(5-(Methylsulfonyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

a) (5)-tert-Butyl2,2-dimethyl-4-(4-(5-(methylthio)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate

The title compound was obtained in analogy to example 6 steps a)-c)using 2-chloro-5-(methylthio)pyrimidine (CAS 115581-36-7) instead of1-bromo-4-chlorobenzene in step c).

Yellow oil. MS (ISP): 445.2 ([M+H]⁺).

b) (4S)-tert-Butyl2,2-dimethyl-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate

To a stirred solution of (5)-tert-butyl2,2-dimethyl-4-(4-(5-(methylthio)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate(393 mg) in dichloromethane (5 ml) was added m-CPB A (218 mg) andstirring was continued at RT for 40 min. The reaction mixture was thendiluted with aq. Na₂SO₃ solution and extracted with dichloromethane. Theorganic layers were dried over MgSO₄ and concentrated in vacuo to give(4S)-tert-butyl2,2-dimethyl-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate(454 mg, 85% purity, 95% yield) as a yellow oil. MS (ISP): 461.4([M+H]⁺), 405.3 ([M+H—C₄H₈—CO₂]⁺).

c) (S)-tert-Butyl2,2-dimethyl-4-(4-(5-(methylsulfonyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate

To a stirred solution of (4S)-tert-butyl2,2-dimethyl-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate(227 mg) in dichloromethane (5 ml) was added m-CPB A (155 mg) andstirring was continued at RT for 40 min. The reaction mixture was thendiluted with aq. Na₂SO₃ solution and extracted with dichloromethane. Theorganic layers were dried over MgSO₄ and concentrated in vacuo to give(S)-tert-butyl2,2-dimethyl-4-(4-(5-(methylsulfonyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate(269 mg, 70% purity, 94% yield) as a brown oil. MS (ISP): 477.4([M+H]⁺), 421.3 ([M+H—C₄H₈—CO₂]⁺).

d)(S)-2-Amino-4-(4-(5-(methylsulfonyl)pyrimidin-2-ylamino)phenyl)butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(S)-tert-butyl2,2-dimethyl-4-(4-(5-(methylsulfonyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylatein place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. White solid. MS (ISP): 337.2 ([M+H]⁺).

e)(S)-4-(4-(5-(Methylsulfonyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 6 step e) using(S)-2-amino-4-(4-(5-(methylsulfonyl)pyrimidin-2-ylamino)phenyl)butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 362.2 ([M+H]⁺).

Example 75(4S)-4-(4-(5-(Methylsulfinyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

a)(2S)-2-Amino-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenyl)butan-1-ol

The title compound was obtained in analogy to example 11 step b) using(4S)-tert-butyl2,2-dimethyl-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenethyl)oxazolidine-3-carboxylate(Example 74b) in place of(S)-2,2-dimethyl-4-{2-[4-(5-trifluoromethyl-pyridin-2-ylamino)-phenyl]-ethyl}-oxazolidine-3-carboxylicacid tert-butyl ester. Yellow oil. MS (ISP): 321.1.2 ([M+H]⁺).

b)(4S)-4-(4-(5-(Methylsulfinyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine

The title compound was obtained in analogy to example 6 step e) using(2S)-2-amino-4-(4-(5-(methylsulfinyl)pyrimidin-2-ylamino)phenyl)butan-1-olinstead of (S)-2-amino-4-[4-(4-chloro-phenylamino)-phenyl]-butan-1-ol.White solid. MS (ISP): 346.2 ([M+H]⁺).

The compounds of formula I and their pharmaceutically usable additionsalts possess valuable pharmacological properties. Specifically,compounds of the present invention have a good affinity to the traceamine associated receptors (TAARs), especially TAAR1.

The compounds were investigated in accordance with the test givenhereinafter.

Materials and Methods Construction of TAAR Expression Plasmids andStably Transfected Cell Lines

For the construction of expression plasmids the coding sequences ofhuman, rat and mouse TAAR 1 were amplified from genomic DNA essentiallyas described by Lindemann et al. [14]. The Expand High Fidelity PCRSystem (Roche Diagnostics) was used with 1.5 mM Mg² and purified PCRproducts were cloned into pCR2.1-TOPO cloning vector (Invitrogen)following the instructions of the manufacturer. PCR products weresubcloned into the pIRESneo2 vector (BD Clontech, Palo Alto, Calif.),and expression vectors were sequence verified before introduction incell lines.

HEK293 cells (ATCC #CRL-1573) were cultured essentially as described byLindemann et al. (2005). For the generation of stably transfected celllines HEK293 cells were transfected with the pIRESneo2 expressionplasmids containing the TAAR coding sequences (described above) withLipofectamine 2000 (Invitrogen) according to the instructions of themanufacturer, and 24 hrs post transfection the culture medium wassupplemented with 1 mg/ml G418 (Sigma, Buchs, Switzerland). After aculture period of about 10 d clones were isolated, expanded and testedfor responsiveness to trace amines (all compounds purchased from Sigma)with the cAMP Biotrak Enzyme immunoassay (EIA) System (Amersham)following the non-acetylation EIA procedure provided by themanufacturer. Monoclonal cell lines which displayed a stable EC₅₀ for aculture period of 15 passages were used for all subsequent studies.

Radioligand Binding Assay on Rat TAAR1 Membrane Preparation andRadioligand Binding.

HEK-293 cells stably expressing rat TAAR1 were maintained at 37° C. and5% CO₂ in DMEM high glucose medium, containing fetal calf serum (10%,heat inactivated for 30 min at 56° C.), penicillin/streptomycin (1%),and 375 μg/ml geneticin (Gibco). Cells were released from culture flasksusing trypsin/EDTA, harvested, washed twice with ice-cold PBS (withoutCa²⁺ and Mg²⁺), pelleted at 1'000 rpm for 5 min at 4° C., frozen andstored at −80° C. Frozen pellets were suspended in 20 ml HEPES-NaOH (20mM, pH 7.4) containing 10 mM EDTA and homogenized with a Polytron (PT6000, Kinematica) at 14'000 rpm for 20 s. The homogenate was centrifugedat 48'000×g for 30 min at 4° C. Subsequently, the supernatant wasremoved and discarded, and the pellet resuspended in 20 ml HEPES-NaOH(20 mM, pH 7.4) containing 0.1 mM EDTA using the Polytron (20 s at14'000 rpm). This procedure was repeated and the final pelletresuspended in HEPES-NaOH containing 0.1 mM EDTA and homogenized usingthe Polytron. Typically, aliquots of 2 ml membrane portions were storedat −80° C. With each new membrane batch the dissociation constant (Kd)was determined via a saturation curve. The TAAR1 radioligand³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylamine(described in WO 2008/098857) was used at a concentration equal to thecalculated Kd value, that was usually around 2.3 nM, resulting in thebinding of approximately 0.2% of the radioligand and a specific bindingrepresenting approximately 85% of the total binding. Nonspecific bindingwas defined as the amount of³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylaminebound in the presence of 10 μM unlabeled ligand. All compounds weretested at a broad range of concentrations (10 pM to 10 μM) induplicates. The test compounds (20 μl/well) were transferred into a 96deep well plate (TreffLab), and 180 μl of HEPES-NaOH (20 mM, pH 7.4)containing MgCl₂ (10 mM) and CaCl₂ (2 mM) (binding buffer), 300 μl ofthe radioligand³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylamine ata concentration of 3.3×Kd in nM and 500 μl of the membranes (resuspendedat 50 μg protein per ml) added. The 96 deep well plates were incubatedfor 1 hr at 4° C. Incubations were terminated by rapid filtrationthrough Unifilter-96 plates (Packard Instrument Company) and glassfilters GF/C (Perkin Elmer) presoaked for 1 hr in polyethylenimine(0.3%) and washed 3 times with 1 ml of cold binding buffer. Afteraddition of 45 μl of Microscint 40 (PerkinElmer) the Unifilter-96 platewas sealed and after 1 hr the radioactivity counted using a TopCountMicroplate Scintillation Counter (Packard Instrument Company).

Radioligand Binding Assay on Mouse TAAR1 Membrane Preparation andRadioligand Binding.

HEK-293 cells stably expressing mouse TAAR1 were maintained at 37° C.and 5% CO₂ in DMEM high glucose medium, containing fetal calf serum(10%, heat inactivated for 30 min at 56° C.), penicillin/streptomycin(1%), and 375 μg/ml geneticin (Gibco). Cells were released from cultureflasks using trypsin/EDTA, harvested, washed twice with ice-cold PBS(without Ca²⁺ and Mg²⁺), pelleted at 1'000 rpm for 5 min at 4° C.,frozen and stored at −80° C. Frozen pellets were suspended in 20 mlHEPES-NaOH (20 mM, pH 7.4) containing 10 mM EDTA and homogenized with aPolytron (PT 6000, Kinematica) at 14'000 rpm for 20 s. The homogenatewas centrifuged at 48'000×g for 30 min at 4° C. Subsequently, thesupernatant was removed and discarded, and the pellet resuspended in 20ml HEPES-NaOH (20 mM, pH 7.4) containing 0.1 mM EDTA using the Polytron(20 s at 14'000 rpm). This procedure was repeated and the final pelletresuspended in HEPES-NaOH containing 0.1 mM EDTA and homogenized usingthe Polytron. Typically, aliquots of 2 ml membrane portions were storedat −80° C. With each new membrane batch the dissociation constant (Kd)was determined via a saturation curve. The TAAR1 radioligand³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylamine(described in WO 2008/098857) was used at a concentration equal to thecalculated Kd value, that was usually around 0.7 nM, resulting in thebinding of approximately 0.5% of the radioligand and a specific bindingrepresenting approximately 70% of the total binding. Nonspecific bindingwas defined as the amount of³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylaminebound in the presence of 10 μM unlabeled ligand. All compounds weretested at a broad range of concentrations (10 pM to 10 μM) induplicates. The test compounds (20 μl/well) were transferred into a 96deep well plate (TreffLab), and 180 μl of HEPES-NaOH (20 mM, pH 7.4)containing MgCl₂ (10 mM) and CaCl₂ (2 mM) (binding buffer), 300 μl ofthe radioligand³[H]-(S)-4-[(ethyl-phenyl-amino)-methyl]-4,5-dihydro-oxazol-2-ylamine ata concentration of 3.3×Kd in nM and 500 μl of the membranes (resuspendedat 60 μg protein per ml) added. The 96 deep well plates were incubatedfor 1 hr at 4° C. Incubations were terminated by rapid filtrationthrough Unifilter-96 plates (Packard Instrument Company) and glassfilters GF/C (Perkin Elmer) presoaked for 1 hr in polyethylenimine(0.3%) and washed 3 times with 1 ml of cold binding buffer. Afteraddition of 45 μl of Microscint 40 (PerkinElmer) the Unifilter-96 platewas sealed and after 1 hr the radioactivity counted using a TopCountMicroplate Scintillation Counter (Packard Instrument Company).

The preferred compounds show a Ki value (gM) in mouse or rat on TAAR1 inthe range of <0.01 μM as shown in the table below.

Ki (μM) Example mouse/rat 1 0.0035/ 0.0006 2 0.0021/ 0.0001 3 0.0022/0.0002 4 0.0021/ 0.0006 5 0.0262/ 0.0033 6 0.0002/ 0.0001 7 0.0017/0.0001 8 0.0002/ 0.0002 9 0.0032/ 0.0002 10 0.0001/ 0.0001 11 0.0002/0.0004 12 0.1111/ — 13 0.0013/ 0.0001 14 0.0008/ 0.0001 15 0.0005/0.0001 16 0.0015/ 0.0004 17 0.0013/ 0.0012 18 0.0012/ 0.0002 19 0.0002/0.0001 20 0.0224/ 0.004 21 0.02/ 0.0005 22 0.0034/ 0.0002 23 0.0003/0.0002 24 0.0182/ 0.0013 25 0.0035/ 0.0007 26 0.0007/ 0.0008 27 0.0182/0.004 28 0.001/ 0.0005 29 0.0306/ 0.0035 30 0.1339/ 0.0083 31 0.0133/0.0059 32 0.0019/ 0.0008 33 0.0096/ 0.0023 34 0.0387/ 0.0026 35 0.0551/0.0023 36 0.0047/ 0.0004 37 0.0013/ 0.0012 38 0.007/ 0.0007 39 0.0128/0.0043 40 0.0024/ 0.001 41 0.0593/ 0.0031 42 0.0008/ 0.0016 43 0.1072/0.0046 44 0.001/ 0.0011 45 0.0077/ 0.0013 46 0.0105/ 0.0012 47 0.0192/0.0024 48 0.0166/ 0.0012 49 0.0007/ 0.0006 50 0.0218/ 0.0006 51 0.0006/0.0004 52 0.0046/ 0.0006 53 0.1127/ 0.0265 54 0.0003/ 0.0004 55 0.005/0.0083 56 0.0019/ 0.0039 57 0.0005/ 0.0004 58 0.0002/ 0.0001 59 0.008/0.0008 60 0.0003/ 0.0002 61 0.0007/ 0.0002 62 0.0623/ 0.0132 63 0.0084/0.0022 64 0.063/ 0.002 65 0.0244/ 0.0032 66 0.023/ 0.0064 67 0.0412/0.0084 68 0.0651/ 0.0265 69 0.0355/ 0.0407 70 0.1341/ 0.0205 71 0.0137/0.0011 72 0.0019/ 0.0007 73 0.02/ 0.0028 74 0.046/ 0.0146 75 0.4802/0.1044

The compounds of formula I and the pharmaceutically acceptable salts ofthe compounds of formula I can be used as medicaments, e.g. in the formof pharmaceutical preparations. The pharmaceutical preparations can beadministered orally, e.g. in the form of tablets, coated tablets,dragés, hard and soft gelatine capsules, solutions, emulsions orsuspensions. The administration can, however, also be effected rectally,e.g. in the form of suppositories, or parenterally, e.g. in the form ofinjection solutions.

The compounds of formula I can be processed with pharmaceutically inert,inorganic or organic carriers for the production of pharmaceuticalpreparations. Lactose, corn starch or derivatives thereof, talc, stearicacids or its salts and the like can be used, for example, as suchcarriers for tablets, coated tablets, dragés and hard gelatine capsules.Suitable carriers for soft gelatine capsules are, for example, vegetableoils, waxes, fats, semi-solid and liquid polyols and the like. Dependingon the nature of the active substance no carriers are however usuallyrequired in the case of soft gelatine capsules. Suitable carriers forthe production of solutions and syrups are, for example, water, polyols,glycerol, vegetable oil and the like. Suitable carriers forsuppositories are, for example, natural or hardened oils, waxes, fats,semi-liquid or liquid polyols and the like.

The pharmaceutical preparations can, moreover, contain preservatives,solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners,colorants, flavorants, salts for varying the osmotic pressure, buffers,masking agents or antioxidants. They can also contain still othertherapeutically valuable substances.

Medicaments containing a compound of formula I or a pharmaceuticallyacceptable salt thereof and a therapeutically inert carrier are also anobject of the present invention, as is a process for their production,which comprises bringing one or more compounds of formula I and/orpharmaceutically acceptable acid addition salts and, if desired, one ormore other therapeutically valuable substances into a galenicaladministration form together with one or more therapeutically inertcarriers.

The most preferred indications in accordance with the present inventionare those which include disorders of the central nervous system, forexample the treatment or prevention of depression, psychosis,Parkinson's disease, anxiety and attention deficit hyperactivitydisorder (ADHD).

The dosage can vary within wide limits and will, of course, have to beadjusted to the individual requirements in each particular case. In thecase of oral administration the dosage for adults can vary from about0.01 mg to about 1000 mg per day of a compound of general formula I orof the corresponding amount of a pharmaceutically acceptable saltthereof. The daily dosage can be administered as single dose or individed doses and, in addition, the upper limit can also be exceededwhen this is found to be indicated.

Tablet Formulation (Wet Granulation) mg/tablet Item Ingredients 5 mg 25mg 100 mg 500 mg 1. Compound of formula I 5 25 100 500 2. LactoseAnhydrous DTG 125 105 30 150 3. Sta-Rx 1500 6 6 6 30 4. MicrocrystallineCellulose 30 30 30 150 5. Magnesium Stearate 1 1 1 1 Total 167 167 167831 Manufacturing Procedure 1. Mix items 1, 2, 3 and 4 and granulatewith purified water. 2. Dry the granules at 50° C. 3. Pass the granulesthrough suitable milling equipment. 4. Add item 5 and mix for threeminutes; compress on a suitable press.

Capsule Formulation mg/capsule Item Ingredients 5 mg 25 mg 100 mg 500mg 1. Compound of formula I 5 25 100 500 2. Hydrous Lactose 159 123 148— 3. Corn Starch 25 35 40 70 4. Talc 10 15 10 25 5. Magnesium Stearate 12 2 5 Total 200 200 300 600 Manufacturing Procedure 1. Mix items 1, 2and 3 in a suitable mixer for 30 minutes. 2. Add items 4 and 5 and mixfor 3 minutes. 3. Fill into a suitable capsule.

1. A compound of formula I

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; X is a bond or CH(CF₃)—; and Ar is heteroaryl, optionallysubstituted by one or more R³; or a pharmaceutically acceptable acidaddition salt thereof.
 2. The compound of claim 1, having formula Ia

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; and Ar is heteroaryl, optionally substituted by one or moreR³; or a pharmaceutically acceptable acid addition salt thereof.
 3. Thecompound of claim 2, wherein Ar is selected from pyridinyl, pyridazinyl,pyrimidinyl, pyrazinyl and quinolinyl.
 4. The compound of claim 3,selected from the group consisting of(S)-4-(4-(Quinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(S)-4-(4-(5-Fluoropyridin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(S)-4-(4-(6-Methylquinolin-8-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-trifluoromethyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyridin-2-yl)-amine;6-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-nicotinonitrile;(S)-4-(4-(6-(Trifluoromethyl)pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-fluoro-pyrimidin-2-yl)-amine;and{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-fluoro-pyridin-2-yl)-amine.5. The compound of claim 3, selected from the group consisting of{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-fluoro-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrimidin-4-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-trifluoromethyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrazin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyridin-2-yl)-amine;and6-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile.6. The compound of claim 3, selected from the group consisting of{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-pyrimidin-4-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methoxy-pyrimidin-4-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-methyl-pyrimidin-4-yl)-amine;(S)-4-(4-(Pyrimidin-4-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methoxy-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethyl-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methoxy-pyrimidin-2-yl)-amine;5-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrazine-2-carbonitrile;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-trifluoromethyl-pyrimidin-2-yl)-amine;and{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(3-chloro-pyrazin-2-yl)-amine.7. The compound of claim 3, selected from the group consisting of{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-4-trifluoromethyl-pyridin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-methyl-pyrazin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(6-chloro-2-methoxy-pyrimidin-4-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methylsulfanyl-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-methyl-pyrimidin-2-yl)-amine;1-(2-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrimidin-5-yl)-ethanone;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(4-methyl-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-propyl-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(2-chloro-pyrimidin-5-yl)-amine;and{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-bromo-pyrimidin-2-yl)-amine.8. The compound of claim 3, selected from the group consisting of{4-[2-((4S,5S)-2-Amino-5-methyl-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-chloro-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-cyclopropyl-pyrimidin-2-yl)-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenyl}-(5-ethoxy-pyrimidin-2-yl)-amine;(S)-4-(4-(5-(Trifluoromethyl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(S)-4-(4-(5-tert-Butylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(S)-4-(4-(5-(Pentan-3-yl)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;2-{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-phenylamino}-pyrimidine-5-carbonitrile;(S)-4-(4-(5-Cyclobutylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(S)-4-(4-(5-Isopropylpyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine;{4-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-2-methyl-phenyl}-(5-chloro-pyrimidin-2-yl)-amineand(S)-4-(4-(5-(2,2,2-Trifluoroethoxy)pyrimidin-2-ylamino)phenethyl)-4,5-dihydrooxazol-2-amine.9. The compound of claim 1, having formula Ib

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; Ar is heteroaryl, optionally substituted by one or more R³;and or a pharmaceutically acceptable acid addition salt thereof.
 10. Thecompound of claim 9, selected from the group consisting of:(4S)-4-(4-(1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine(1:1 mixture of epimers);(+)-(S)-4-(4-((S)-1-(4-Chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine;(−)-(S)-4-(4-((R)-1-(4-chlorophenyl)-2,2,2-trifluoroethylamino)phenethyl)-4,5-dihydrooxazol-2-amine;-4-(4-(2,2,2-Trifluoro-1-(3-fluorophenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amineand(4S)-4-(4-(2,2,2-Trifluoro-1-(4-(trifluoromethyl)phenyl)ethylamino)phenethyl)-4,5-dihydrooxazol-2-amine.11. The compound of claim 9, wherein Ar is selected from pyridinyl,pyridazinyl, pyrimidinyl, pyrazinyl and quinolinyl.
 12. The compound ofclaim 11, which compound is{5-[2-((S)-2-Amino-4,5-dihydro-oxazol-4-yl)-ethyl]-pyridin-2-yl}-(5-chloro-pyrimidin-2-yl)-amine.13. A pharmaceutical composition comprising a compound of formula I

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; X is a bond or CH(CF₃)—; and Ar is heteroaryl, optionallysubstituted by one or more R³; or a pharmaceutically acceptable acidaddition salt thereof and a pharmaceutically acceptable carrier.
 14. Thecomposition of claim 13, wherein the compound of formula I is a compoundof formula Ia.

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; and Ar is heteroaryl, optionally substituted by one or moreR³; or a pharmaceutically acceptable acid addition salt thereof.
 15. Thecomposition of claim 13, wherein the compound of formula I is a compoundof formula Ib.

wherein R¹ is hydrogen or lower alkyl; R² is hydrogen; R³ is hydrogen,halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy,lower alkoxy substituted by halogen, cyano, S-lower alkyl, S(O)-loweralkyl, S(O)₂-lower alkyl, C(O)-lower alkyl or C₃₋₆-cycloalkyl; R⁴ ishydrogen or lower alkyl;

is phenyl; Ar is heteroaryl, optionally substituted by one or more R³;and or a pharmaceutically acceptable acid addition salt thereof.